Ori,
_tagDialogFeature specifies the window ornaments for the dialog box. If you want to modify the dialog window size "on-the-fly", you need to set the value of _tagDialogFeature dynamically.
Hope it helps.
Let me know if you have any further questions.
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