ytang,
>>How can I disable the double click action in the ASP version?
No. This double click function can be disabled.
>>Or, is there any way to customize the double click action to pop up a custom dialog?
No.
I think you need to modify the insertImage.asp direclty.
You can add a custom dialog:
asp.net Chat http://cutesoft.net/ASP.NET+Chat/default.aspx
Web Messenger: http://cutesoft.net/Web-Messenger/default.aspx
asp.net wysiwyg editor: http://cutesoft.net/ASP.NET+WYSIWYG+Editor/default.aspx
asp wysiwyg html editor: http://cutesoft.net/ASP
asp.net Image Gallery: http://cutesoft.net/ASP.NET+Image+Gallery/default.aspx
Live Support: http://cutesoft.net/live-support/default.aspx