diff --git a/src/editor.hxx b/src/editor.hxx
index d6dd619..97ddcf5 100644
--- a/src/editor.hxx
+++ b/src/editor.hxx
@@ -9,9 +9,12 @@
 #include <QSyntaxHighlighter>
 #include <QRegularExpression>
 #include <QRegularExpressionMatch>
+#include <cassert>
 
 class Highlighter: public QSyntaxHighlighter {
     Q_OBJECT;
+  Q_SIGNALS:
+    void include(QString);
   public:
     Highlighter(QTextDocument *parent): QSyntaxHighlighter(parent) {
       QString commands="auth|ca-certificate|call|case|check|clear-cookies|click|clicktype|client-certificate|do|download|echo|execute|exists|exit|expect|fail|for|function|if|ignoreto|include|label|load|not|offline-storage-path|open|screenshot|set|setvalue|sleep|testcase|testsuite|timeout|unset|upload";
@@ -20,6 +23,18 @@ class Highlighter: public QSyntaxHighlighter {
     }
   protected:
     void highlightBlock(const QString &text) {
+      static QRegularExpression inc("^ *include +([^ ].*.\\.wt)");
+      QRegularExpressionMatch m(inc.match(text));
+      if (m.hasMatch()) {
+        QTextCharFormat fmt;
+        if (QFile(m.captured(1)).exists()) {
+          fmt.setForeground(Qt::darkGreen);
+        } else {
+          fmt.setForeground(Qt::darkRed);
+        }
+        setFormat(m.capturedStart(1), m.capturedLength(1), fmt);
+        include(m.captured(1));
+      }
       for (auto e: _expressions) {
         auto m(e.re.match(text));
         for (int i(0); i<=m.lastCapturedIndex(); ++i) {
@@ -53,13 +68,16 @@ class LineNumberArea: public QWidget {
 
 class CodeEditor: public QPlainTextEdit {
     Q_OBJECT;
+  Q_SIGNALS:
+    void include(QString);
   public:
     CodeEditor(QWidget *parent = 0): QPlainTextEdit(parent) {
-      new Highlighter(document());
+      Highlighter *highlighter(new Highlighter(document()));
       lineNumberArea = new LineNumberArea(this);
-      connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateLineNumberAreaWidth(int)));
-      connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateLineNumberArea(QRect,int)));
-      connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));
+      assert(connect(this, SIGNAL(blockCountChanged(int)), SLOT(updateLineNumberAreaWidth(int))));
+      assert(connect(this, SIGNAL(updateRequest(QRect,int)), SLOT(updateLineNumberArea(QRect,int))));
+      assert(connect(this, SIGNAL(cursorPositionChanged()), SLOT(highlightCurrentLine())));
+      assert(connect(highlighter, SIGNAL(include(QString)), SIGNAL(include(QString))));
       updateLineNumberAreaWidth(0);
       highlightCurrentLine();
     }
diff --git a/src/makefile.am b/src/makefile.am
index 19cfa52..adb16bd 100644
--- a/src/makefile.am
+++ b/src/makefile.am
@@ -8,9 +8,9 @@
 
 bin_PROGRAMS = webtester webrunner
 
-webtester_MOCFILES = moc_testgui.cxx moc_commands.cxx moc_webpage.cxx	\
+webtester_MOCFILES = moc_testgui.cxx moc_scriptfile.cxx moc_commands.cxx moc_webpage.cxx	\
                      moc_networkaccessmanager.cxx moc_editor.cxx
-webtester_UIFILES = ui_testgui.hxx
+webtester_UIFILES = ui_testgui.hxx ui_scriptfile.hxx
 webtester_SOURCES = version.cxx webtester.cxx exceptions.hxx version.hxx \
                     ${webtester_MOCFILES} ${webtester_UIFILES}
 
diff --git a/src/testgui.hxx b/src/testgui.hxx
index f74c719..22fb565 100644
--- a/src/testgui.hxx
+++ b/src/testgui.hxx
@@ -10,6 +10,7 @@
 #include <webpage.hxx>
 #include <editor.hxx>
 #include <commands.hxx>
+#include <scriptfile.hxx>
 #include <QMainWindow>
 #include <QSettings>
 #include <QWebFrame>
@@ -63,11 +64,12 @@ class TestGUI: public QMainWindow, protected Ui::TestGUI {
       _web->installEventFilter(this); // track mouse and keyboard
       page->setForwardUnsupportedContent(true);
       _commands->setText(Script().commands(Script::HTML));
-      connect(page, SIGNAL(uploadFile(QString)), SLOT(uploadFile(QString)));
-      connect(page, SIGNAL(unsupportedContent(QNetworkReply*)),
-              SLOT(unsupportedContent(QNetworkReply*)));
-      connect(page, SIGNAL(downloadRequested(const QNetworkRequest&)),
-              SLOT(downloadRequested(const QNetworkRequest&)));
+      assert(connect(page, SIGNAL(uploadFile(QString)), SLOT(uploadFile(QString))));
+      assert(connect(page, SIGNAL(unsupportedContent(QNetworkReply*)),
+                     SLOT(unsupportedContent(QNetworkReply*))));
+      assert(connect(page, SIGNAL(downloadRequested(const QNetworkRequest&)),
+                     SLOT(downloadRequested(const QNetworkRequest&))));
+      assert(connect(_testscript, SIGNAL(include(QString)), SLOT(include(QString))));
       if (setupScript.size()) loadSetup(setupScript);
       if (scriptFile.size()) loadFile(scriptFile);
     }
@@ -338,6 +340,32 @@ class TestGUI: public QMainWindow, protected Ui::TestGUI {
       if (!vb) return;
       vb->setValue(vb->maximum());
     }
+    void include(QString name) {
+      if (_testscripts.contains(name)) return;
+      _testscripts[name] = new ScriptFile(this);
+      assert(connect(_testscripts[name], SIGNAL(include(QString)), SLOT(include(QString))));
+      assert(connect(_testscripts[name], SIGNAL(close(ScriptFile*)), SLOT(remove(ScriptFile*))));
+      QFile file(name);
+      try {
+        if (!file.open(QIODevice::ReadOnly|QIODevice::Text))
+          throw std::runtime_error("file open failed");
+        _testscripts[name]->editor()->setPlainText(QString::fromUtf8(file.readAll()));
+        if (file.error()!=QFileDevice::NoError)
+          throw std::runtime_error("file read failed");
+        _testscripts[name]->name(name);
+        tabifyDockWidget(_scriptDock, _testscripts[name]);
+        QDockWidget* d(0);
+        for (QWidget* w(QApplication::focusWidget()); w&&!(d=qobject_cast<QDockWidget*>(w));
+             w=qobject_cast<QWidget*>(w->parent()));
+        if (d) d->raise();
+      } catch(const std::exception& x) {
+        remove(_testscripts[name]);
+      }
+    }
+    void remove(ScriptFile* scriptfile) {
+      _testscripts.remove(scriptfile->name());
+      delete scriptfile;
+    }
   protected:
     void closeEvent(QCloseEvent* event) {
       QSettings settings("mrw", "webtester");
@@ -452,7 +480,7 @@ class TestGUI: public QMainWindow, protected Ui::TestGUI {
     void loadFile(QString name) {
       QFile file(name);
       try {
-        if (!file.open(QIODevice::ReadOnly | QIODevice::Text))
+        if (!file.open(QIODevice::ReadOnly|QIODevice::Text))
           throw std::runtime_error("file open failed");
         _testscript->setPlainText(QString::fromUtf8(file.readAll()));
         if (file.error()!=QFileDevice::NoError)
@@ -900,6 +928,7 @@ class TestGUI: public QMainWindow, protected Ui::TestGUI {
     bool _typing; // user is typing
     bool _inEventFilter; // actually handling event filter
     Script _setupScript;
+    QMap<QString, ScriptFile*> _testscripts;
 };
 
 #endif // TESTGUI_HXX
diff --git a/src/testgui.ui b/src/testgui.ui
index 6334dbd..b8f764a 100644
--- a/src/testgui.ui
+++ b/src/testgui.ui
@@ -134,7 +134,7 @@
   <widget class="QStatusBar" name="statusbar"/>
   <widget class="QDockWidget" name="_domDock">
    <property name="windowTitle">
-    <string>DOM Tree</string>
+    <string>D&amp;OM Tree</string>
    </property>
    <attribute name="dockWidgetArea">
     <number>2</number>
@@ -158,7 +158,7 @@
   </widget>
   <widget class="QDockWidget" name="_sourceDock">
    <property name="windowTitle">
-    <string>HTML Source</string>
+    <string>HTML &amp;Source</string>
    </property>
    <attribute name="dockWidgetArea">
     <number>8</number>
@@ -596,7 +596,7 @@ this.dispatchEvent(evObj);</string>
       </layout>
      </item>
      <item>
-      <widget class="QPlainTextEdit" name="_setupscript"/>
+      <widget class="CodeEditor" name="_setupscript"/>
      </item>
     </layout>
    </widget>