diff --git a/src/dialog/vdirinfodialog.cpp b/src/dialog/vdirinfodialog.cpp
index a93d3d6d..608f0961 100644
--- a/src/dialog/vdirinfodialog.cpp
+++ b/src/dialog/vdirinfodialog.cpp
@@ -1,16 +1,23 @@
 #include <QtWidgets>
 #include "vdirinfodialog.h"
+#include "vdirectory.h"
+#include "vconfigmanager.h"
 
-VDirInfoDialog::VDirInfoDialog(const QString &title, const QString &info,
-                               const QString &defaultName,
+extern VConfigManager *g_config;
+
+VDirInfoDialog::VDirInfoDialog(const QString &title,
+                               const QString &info,
+                               const VDirectory *directory,
+                               VDirectory *parentDirectory,
                                QWidget *parent)
-    : QDialog(parent), infoLabel(NULL), title(title), info(info), defaultName(defaultName)
+    : QDialog(parent), infoLabel(NULL), title(title), info(info),
+      m_directory(directory), m_parentDirectory(parentDirectory)
 {
     setupUI();
 
-    connect(nameEdit, &QLineEdit::textChanged, this, &VDirInfoDialog::enableOkButton);
+    connect(nameEdit, &QLineEdit::textChanged, this, &VDirInfoDialog::handleInputChanged);
 
-    enableOkButton();
+    handleInputChanged();
 }
 
 void VDirInfoDialog::setupUI()
@@ -19,10 +26,14 @@ void VDirInfoDialog::setupUI()
         infoLabel = new QLabel(info);
     }
     nameLabel = new QLabel(tr("Folder &name:"));
-    nameEdit = new QLineEdit(defaultName);
+    nameEdit = new QLineEdit(m_directory->getName());
     nameEdit->selectAll();
     nameLabel->setBuddy(nameEdit);
 
+    m_warnLabel = new QLabel();
+    m_warnLabel->setWordWrap(true);
+    m_warnLabel->hide();
+
     // Ok is the default button.
     m_btnBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
     connect(m_btnBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
@@ -40,6 +51,7 @@ void VDirInfoDialog::setupUI()
         mainLayout->addWidget(infoLabel);
     }
     mainLayout->addLayout(topLayout);
+    mainLayout->addWidget(m_warnLabel);
     mainLayout->addWidget(m_btnBox);
     mainLayout->setSizeConstraint(QLayout::SetFixedSize);
     setLayout(mainLayout);
@@ -47,10 +59,28 @@ void VDirInfoDialog::setupUI()
     setWindowTitle(title);
 }
 
-void VDirInfoDialog::enableOkButton()
+void VDirInfoDialog::handleInputChanged()
 {
+    bool showWarnLabel = false;
+    QString name = nameEdit->text();
+    bool nameOk = !name.isEmpty();
+    if (nameOk && name != m_directory->getName()) {
+        // Check if the name conflicts with existing directory name.
+        // Case-insensitive when creating note.
+        if (m_parentDirectory->findSubDirectory(name, false)) {
+            nameOk = false;
+            showWarnLabel = true;
+            QString nameConflictText = tr("<span style=\"%1\">WARNING</span>: Name (case-insensitive) already exists. "
+                                          "Please choose another name.")
+                                          .arg(g_config->c_warningTextStyle);
+            m_warnLabel->setText(nameConflictText);
+        }
+    }
+
+    m_warnLabel->setVisible(showWarnLabel);
+
     QPushButton *okBtn = m_btnBox->button(QDialogButtonBox::Ok);
-    okBtn->setEnabled(!nameEdit->text().isEmpty());
+    okBtn->setEnabled(nameOk);
 }
 
 QString VDirInfoDialog::getNameInput() const
diff --git a/src/dialog/vdirinfodialog.h b/src/dialog/vdirinfodialog.h
index f3df2b6e..5078b9cc 100644
--- a/src/dialog/vdirinfodialog.h
+++ b/src/dialog/vdirinfodialog.h
@@ -7,17 +7,22 @@ class QLabel;
 class QLineEdit;
 class QDialogButtonBox;
 class QString;
+class VDirectory;
 
 class VDirInfoDialog : public QDialog
 {
     Q_OBJECT
 public:
-    VDirInfoDialog(const QString &title, const QString &info, const QString &defaultName,
+    VDirInfoDialog(const QString &title,
+                   const QString &info,
+                   const VDirectory *directory,
+                   VDirectory *parentDirectory,
                    QWidget *parent = 0);
+
     QString getNameInput() const;
 
 private slots:
-    void enableOkButton();
+    void handleInputChanged();
 
 private:
     void setupUI();
@@ -25,10 +30,13 @@ private:
     QLabel *infoLabel;
     QLabel *nameLabel;
     QLineEdit *nameEdit;
+    QLabel *m_warnLabel;
     QDialogButtonBox *m_btnBox;
 
     QString title;
     QString info;
-    QString defaultName;
+
+    VDirectory *m_parentDirectory;
+    const VDirectory *m_directory;
 };
 #endif // VDIRINFODIALOG_H
diff --git a/src/dialog/vfileinfodialog.cpp b/src/dialog/vfileinfodialog.cpp
index 1c26469e..b7087770 100644
--- a/src/dialog/vfileinfodialog.cpp
+++ b/src/dialog/vfileinfodialog.cpp
@@ -65,7 +65,7 @@ void VFileInfoDialog::handleInputChanged()
     QString name = nameEdit->text();
     bool nameOk = !name.isEmpty();
     if (nameOk && name != m_file->getName()) {
-        // Check if the name conflicts with existing notebook name.
+        // Check if the name conflicts with existing note name.
         // Case-insensitive when creating note.
         if (m_directory->findFile(name, false)) {
             nameOk = false;
diff --git a/src/dialog/vnewdirdialog.cpp b/src/dialog/vnewdirdialog.cpp
index 89d57f70..353bac8c 100644
--- a/src/dialog/vnewdirdialog.cpp
+++ b/src/dialog/vnewdirdialog.cpp
@@ -1,13 +1,23 @@
 #include <QtWidgets>
 #include "vnewdirdialog.h"
+#include "vdirectory.h"
+#include "vconfigmanager.h"
 
-VNewDirDialog::VNewDirDialog(const QString &title, const QString &info, const QString &name, const QString &defaultName,
+extern VConfigManager *g_config;
+
+VNewDirDialog::VNewDirDialog(const QString &title,
+                             const QString &info,
+                             const QString &defaultName,
+                             VDirectory *directory,
                              QWidget *parent)
-    : QDialog(parent), title(title), info(info), name(name), defaultName(defaultName)
+    : QDialog(parent), title(title), info(info), defaultName(defaultName),
+      m_directory(directory)
 {
     setupUI();
 
-    connect(nameEdit, &QLineEdit::textChanged, this, &VNewDirDialog::enableOkButton);
+    connect(nameEdit, &QLineEdit::textChanged, this, &VNewDirDialog::handleInputChanged);
+
+    handleInputChanged();
 }
 
 void VNewDirDialog::setupUI()
@@ -18,11 +28,15 @@ void VNewDirDialog::setupUI()
         infoLabel->setWordWrap(true);
     }
 
-    nameLabel = new QLabel(name);
+    QLabel *nameLabel = new QLabel("Folder &name:");
     nameEdit = new QLineEdit(defaultName);
     nameEdit->selectAll();
     nameLabel->setBuddy(nameEdit);
 
+    m_warnLabel = new QLabel();
+    m_warnLabel->setWordWrap(true);
+    m_warnLabel->hide();
+
     // Ok is the default button.
     m_btnBox = new QDialogButtonBox(QDialogButtonBox::Ok | QDialogButtonBox::Cancel);
     connect(m_btnBox, &QDialogButtonBox::accepted, this, &QDialog::accept);
@@ -40,16 +54,35 @@ void VNewDirDialog::setupUI()
         mainLayout->addWidget(infoLabel);
     }
     mainLayout->addLayout(topLayout);
+    mainLayout->addWidget(m_warnLabel);
     mainLayout->addWidget(m_btnBox);
     mainLayout->setSizeConstraint(QLayout::SetFixedSize);
     setLayout(mainLayout);
     setWindowTitle(title);
 }
 
-void VNewDirDialog::enableOkButton(const QString &editText)
+void VNewDirDialog::handleInputChanged()
 {
+    bool showWarnLabel = false;
+    QString name = nameEdit->text();
+    bool nameOk = !name.isEmpty();
+    if (nameOk) {
+        // Check if the name conflicts with existing directory name.
+        // Case-insensitive when creating folder.
+        if (m_directory->findSubDirectory(name, false)) {
+            nameOk = false;
+            showWarnLabel = true;
+            QString nameConflictText = tr("<span style=\"%1\">WARNING</span>: Name (case-insensitive) already exists. "
+                                          "Please choose another name.")
+                                          .arg(g_config->c_warningTextStyle);
+            m_warnLabel->setText(nameConflictText);
+        }
+    }
+
+    m_warnLabel->setVisible(showWarnLabel);
+
     QPushButton *okBtn = m_btnBox->button(QDialogButtonBox::Ok);
-    okBtn->setEnabled(!editText.isEmpty());
+    okBtn->setEnabled(nameOk);
 }
 
 QString VNewDirDialog::getNameInput() const
diff --git a/src/dialog/vnewdirdialog.h b/src/dialog/vnewdirdialog.h
index bef785df..30ca9727 100644
--- a/src/dialog/vnewdirdialog.h
+++ b/src/dialog/vnewdirdialog.h
@@ -7,29 +7,36 @@ class QLabel;
 class QLineEdit;
 class QDialogButtonBox;
 class QString;
+class VDirectory;
 
 class VNewDirDialog : public QDialog
 {
     Q_OBJECT
 public:
-    VNewDirDialog(const QString &title, const QString &info, const QString &name,
-                  const QString &defaultName, QWidget *parent = 0);
+    VNewDirDialog(const QString &title,
+                  const QString &info,
+                  const QString &defaultName,
+                  VDirectory *directory,
+                  QWidget *parent = 0);
+
     QString getNameInput() const;
 
 private slots:
-    void enableOkButton(const QString &editText);
+    void handleInputChanged();
 
 private:
     void setupUI();
 
-    QLabel *nameLabel;
     QLineEdit *nameEdit;
     QDialogButtonBox *m_btnBox;
 
+    QLabel *m_warnLabel;
+
     QString title;
     QString info;
-    QString name;
     QString defaultName;
+
+    VDirectory *m_directory;
 };
 
 #endif // VNEWDIRDIALOG_H
diff --git a/src/dialog/vnewfiledialog.cpp b/src/dialog/vnewfiledialog.cpp
index 0342ff70..69009ff7 100644
--- a/src/dialog/vnewfiledialog.cpp
+++ b/src/dialog/vnewfiledialog.cpp
@@ -77,7 +77,7 @@ void VNewFileDialog::handleInputChanged()
     QString name = nameEdit->text();
     bool nameOk = !name.isEmpty();
     if (nameOk) {
-        // Check if the name conflicts with existing notebook name.
+        // Check if the name conflicts with existing note name.
         // Case-insensitive when creating note.
         if (m_directory->findFile(name, false)) {
             nameOk = false;
diff --git a/src/vdirectorytree.cpp b/src/vdirectorytree.cpp
index 4da4c6a2..60bb4081 100644
--- a/src/vdirectorytree.cpp
+++ b/src/vdirectorytree.cpp
@@ -388,35 +388,24 @@ void VDirectoryTree::newSubDirectory()
 
     QString info = tr("Create a subfolder in <span style=\"%1\">%2</span>.")
                      .arg(g_config->c_dataTextStyle).arg(curDir->getName());
-    QString text(tr("Folder &name:"));
-    QString defaultText("new_folder");
+    QString defaultName("new_folder");
+    defaultName = VUtils::getFileNameWithSequence(curDir->fetchPath(), defaultName);
+    VNewDirDialog dialog(tr("Create Folder"), info, defaultName, curDir, this);
+    if (dialog.exec() == QDialog::Accepted) {
+        QString name = dialog.getNameInput();
 
-    do {
-        VNewDirDialog dialog(tr("Create Folder"), info, text, defaultText, this);
-        if (dialog.exec() == QDialog::Accepted) {
-            QString name = dialog.getNameInput();
-            // Case-insensitive.
-            if (curDir->findSubDirectory(name, false)) {
-                info = tr("Name (case-insensitive) already exists in "
-                          "<span style=\"%1\">%2</span>. Please choose another name.")
-                         .arg(g_config->c_dataTextStyle).arg(curDir->getName());
-                defaultText = name;
-                continue;
-            }
-
-            VDirectory *subDir = curDir->createSubDirectory(name);
-            if (!subDir) {
-                VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
-                                    tr("Fail to create folder <span style=\"%1\">%2</span>.")
-                                      .arg(g_config->c_dataTextStyle).arg(name), "",
-                                    QMessageBox::Ok, QMessageBox::Ok, this);
-                return;
-            }
-            updateItemChildren(curItem);
-            locateDirectory(subDir);
+        VDirectory *subDir = curDir->createSubDirectory(name);
+        if (!subDir) {
+            VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
+                                tr("Fail to create folder <span style=\"%1\">%2</span>.")
+                                  .arg(g_config->c_dataTextStyle).arg(name), "",
+                                QMessageBox::Ok, QMessageBox::Ok, this);
+            return;
         }
-        break;
-    } while (true);
+
+        updateItemChildren(curItem);
+        locateDirectory(subDir);
+    }
 }
 
 void VDirectoryTree::newRootDirectory()
@@ -426,33 +415,25 @@ void VDirectoryTree::newRootDirectory()
     }
     QString info = tr("Create a root folder in notebook <span style=\"%1\">%2</span>.")
                      .arg(g_config->c_dataTextStyle).arg(m_notebook->getName());
-    QString text(tr("Folder &name:"));
-    QString defaultText("new_folder");
     VDirectory *rootDir = m_notebook->getRootDir();
-    do {
-        VNewDirDialog dialog(tr("Create Root Folder"), info, text, defaultText, this);
-        if (dialog.exec() == QDialog::Accepted) {
-            QString name = dialog.getNameInput();
-            if (rootDir->findSubDirectory(name, false)) {
-                info = tr("Name (case-insensitive) already exists in "
-                          "notebook <span style=\"%1\">%2</span>. Please choose another name.")
-                         .arg(g_config->c_dataTextStyle).arg(m_notebook->getName());
-                defaultText = name;
-                continue;
-            }
-            VDirectory *subDir = rootDir->createSubDirectory(name);
-            if (!subDir) {
-                VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
-                                    tr("Fail to create folder <span style=\"%1\">%2</span>.")
-                                      .arg(g_config->c_dataTextStyle).arg(name), "",
-                                    QMessageBox::Ok, QMessageBox::Ok, this);
-                return;
-            }
-            updateItemChildren(NULL);
-            locateDirectory(subDir);
+    QString defaultName("new_folder");
+    defaultName = VUtils::getFileNameWithSequence(rootDir->fetchPath(), defaultName);
+    VNewDirDialog dialog(tr("Create Root Folder"), info, defaultName, rootDir, this);
+    if (dialog.exec() == QDialog::Accepted) {
+        QString name = dialog.getNameInput();
+
+        VDirectory *subDir = rootDir->createSubDirectory(name);
+        if (!subDir) {
+            VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
+                                tr("Fail to create folder <span style=\"%1\">%2</span>.")
+                                  .arg(g_config->c_dataTextStyle).arg(name), "",
+                                QMessageBox::Ok, QMessageBox::Ok, this);
+            return;
         }
-        break;
-    } while (true);
+
+        updateItemChildren(NULL);
+        locateDirectory(subDir);
+    }
 }
 
 void VDirectoryTree::deleteDirectory()
@@ -503,36 +484,26 @@ void VDirectoryTree::editDirectoryInfo()
     VDirectory *curDir = getVDirectory(curItem);
     VDirectory *parentDir = curDir->getParentDirectory();
     QString curName = curDir->getName();
-    QString info;
-    QString defaultName = curName;
 
-    do {
-        VDirInfoDialog dialog(tr("Folder Information"), info, defaultName, this);
-        if (dialog.exec() == QDialog::Accepted) {
-            QString name = dialog.getNameInput();
-            if (name == curName) {
-                return;
-            }
-
-            if (parentDir->findSubDirectory(name, false)) {
-                info = "Name (case-insensitive) already exists. Please choose another name.";
-                defaultName = name;
-                continue;
-            }
-
-            if (!curDir->rename(name)) {
-                VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
-                                    tr("Fail to rename folder <span style=\"%1\">%2</span>.")
-                                      .arg(g_config->c_dataTextStyle).arg(curName), "",
-                                    QMessageBox::Ok, QMessageBox::Ok, this);
-                return;
-            }
-            curItem->setText(0, name);
-            curItem->setToolTip(0, name);
-            emit directoryUpdated(curDir);
+    VDirInfoDialog dialog(tr("Folder Information"), "", curDir, parentDir, this);
+    if (dialog.exec() == QDialog::Accepted) {
+        QString name = dialog.getNameInput();
+        if (name == curName) {
+            return;
         }
-        break;
-    } while (true);
+
+        if (!curDir->rename(name)) {
+            VUtils::showMessage(QMessageBox::Warning, tr("Warning"),
+                                tr("Fail to rename folder <span style=\"%1\">%2</span>.")
+                                  .arg(g_config->c_dataTextStyle).arg(curName), "",
+                                QMessageBox::Ok, QMessageBox::Ok, this);
+            return;
+        }
+
+        curItem->setText(0, name);
+        curItem->setToolTip(0, name);
+        emit directoryUpdated(curDir);
+    }
 }
 
 void VDirectoryTree::openDirectoryLocation() const