diff --git a/uppsrc/Core/AString.hpp b/uppsrc/Core/AString.hpp
index e1c2d6e73..cb132a38f 100644
--- a/uppsrc/Core/AString.hpp
+++ b/uppsrc/Core/AString.hpp
@@ -106,7 +106,8 @@ void AString<B>::Replace(const tchar *find, int findlen, const tchar *replace, i
 		i = j + findlen;
 	}
 	r.Cat(p + i, B::GetCount() - i);
-	*this = r;
+	Free();
+	Set(r);
 }
 
 template <class B>
diff --git a/uppsrc/Core/String.h b/uppsrc/Core/String.h
index dabeff14e..32a084a1d 100644
--- a/uppsrc/Core/String.h
+++ b/uppsrc/Core/String.h
@@ -670,6 +670,8 @@ public:
 
 	WString0()                           { Zero(); }
 	~WString0()                          { Free(); }
+
+	WString0& operator=(const WString0& s) { Free(); Set(s); return *this; }
 };
 
 class WString : public Moveable<WString, AString<WString0> >
diff --git a/uppsrc/ide/ide.h b/uppsrc/ide/ide.h
index 00bb4aedc..9f7d8c856 100644
--- a/uppsrc/ide/ide.h
+++ b/uppsrc/ide/ide.h
@@ -874,6 +874,9 @@ public:
 		void  TextInitCaps();
 		void  SwapCase();
 		void  ToCString();
+		void  ToComment();
+		void  CommentLines();
+		void  UnComment();
 
 	void      MacroMenu(Bar& menu);
 		bool  HasMacros();
diff --git a/uppsrc/ide/ide.key b/uppsrc/ide/ide.key
index 5fa6c0cb1..68dfc091b 100644
--- a/uppsrc/ide/ide.key
+++ b/uppsrc/ide/ide.key
@@ -108,6 +108,9 @@ KEY(INITCAPS, "Capitalize the first character of words", 0)
 KEY(SWAPCASE, "Swap case", 0)
 KEY(TOASCII, "To ASCII", 0)
 KEY(TOCSTRING, "Convert to C string", 0)
+KEY(TOCOMMENT, "Comment code", K_ALT_K)
+KEY(COMMENTLINES, "Comment code lines", K_SHIFT|K_ALT_K)
+KEY(UNCOMMENT, "Uncomment code", K_CTRL_K|K_ALT_K)
 
 KEY(DIFF, "Compare with file..", 0)
 KEY(SVNDIFF, "Show svn history of file..", 0)
diff --git a/uppsrc/ide/idebar.cpp b/uppsrc/ide/idebar.cpp
index d88838789..6ec8614b6 100644
--- a/uppsrc/ide/idebar.cpp
+++ b/uppsrc/ide/idebar.cpp
@@ -109,19 +109,24 @@ void Ide::EditSpecial(Bar& menu)
 	    .Help("Copy the current identifier to the clipboard");
 	menu.Add(AK_FORMATCODE, THISBACK(FormatCode))
 	    .Help("Reformat code in editor");
-	menu.Add(AK_TOUPPER, THISBACK(TextToUpper))
+	menu.Add(editor.IsSelection(), AK_TOUPPER, THISBACK(TextToUpper))
 	    .Help("Convert letters in selection to uppercase"); 
-	menu.Add(AK_TOLOWER, THISBACK(TextToLower))
+	menu.Add(editor.IsSelection(), AK_TOLOWER, THISBACK(TextToLower))
 	    .Help("Convert letters in selection to lowercase"); 
-	menu.Add(AK_TOASCII, THISBACK(TextToAscii))
+	menu.Add(editor.IsSelection(), AK_TOASCII, THISBACK(TextToAscii))
 		.Help("Covert text to 7-bit ASCII removing all accents and special symbols");
-	menu.Add(AK_INITCAPS, THISBACK(TextInitCaps))
+	menu.Add(editor.IsSelection(), AK_INITCAPS, THISBACK(TextInitCaps))
 	    .Help("Capitalize the first character of words in selection"); 
-	menu.Add(AK_SWAPCASE, THISBACK(SwapCase))
+	menu.Add(editor.IsSelection(), AK_SWAPCASE, THISBACK(SwapCase))
 	    .Help("Swap the case of letters in selection"); 
-	menu.Add(AK_TOCSTRING, THISBACK(ToCString))
+	menu.Add(editor.IsSelection(), AK_TOCSTRING, THISBACK(ToCString))
 	    .Help("Convert selection to CString");
-}
+	menu.Add(editor.IsSelection(), AK_TOCOMMENT, THISBACK(ToComment))
+		.Help("Comment code");
+	menu.Add(editor.IsSelection(), AK_COMMENTLINES, THISBACK(CommentLines))
+		.Help("Comment code lines");
+	menu.Add(editor.IsSelection(), AK_UNCOMMENT, THISBACK(UnComment))
+		.Help("Uncomment code");}
 
 void Ide::SearchMenu(Bar& menu)
 {
diff --git a/uppsrc/ide/idetool.cpp b/uppsrc/ide/idetool.cpp
index 11c810dfc..1e2661220 100644
--- a/uppsrc/ide/idetool.cpp
+++ b/uppsrc/ide/idetool.cpp
@@ -240,14 +240,14 @@ String FormatElapsedTime(double run)
 
 void Ide::AlterText(WString (*op)(const WString& in))
 {
-	if(designer)
+	if(designer || !editor.IsSelection())
 		return;
 	editor.NextUndo();
-	if(!editor.IsSelection())
-		editor.SelectAll();
 	WString w = editor.GetSelectionW();
 	editor.RemoveSelection();
+	int l = editor.GetCursor();
 	editor.Paste((*op)(w));
+	editor.SetSelection(l, editor.GetCursor());
 }
 
 void Ide::TextToUpper()
@@ -294,6 +294,52 @@ void Ide::ToCString()
 	AlterText(sCString);
 }
 
+static WString sComment(const WString& s) 
+{
+	return "/*" + s + "*/";
+}
+
+void Ide::ToComment()
+{
+	AlterText(sComment);
+}
+
+static WString sCommentLines(const WString& s)
+{
+	String r;
+	StringStream ss(s.ToString());
+	for(;;) {
+		String line = ss.GetLine();
+		if(ss.IsError())
+			return s;
+		else
+		if(!line.IsVoid())
+			r << "//" << line << "\n";
+		if(ss.IsEof())
+			break;
+	}
+	return r.ToWString();
+}
+
+void Ide::CommentLines()
+{
+	AlterText(sCommentLines);
+}
+
+static WString sUncomment(const WString& s) 
+{
+	WString h = s;
+	h.Replace("/*", "");
+	h.Replace("//", "");
+	h.Replace("*/", "");
+	return h;
+}
+
+void Ide::UnComment()
+{
+	AlterText(sUncomment);
+}
+
 void Ide::Times()
 {
 	WithStatisticsLayout<TopWindow> statdlg;