I don't know what you means but you can try this:
Code:
<input id="bnClick1" type=button onclick="window.showModalDialog('webform2.aspx');">
	<input id="bnClick2" type=button onclick="window.showModelessDialog('webform2.aspx');">
	<input id="bnClick3" type=button onclick="window.open('webform2.aspx');">
with bnClick1: IE4.0 or higher
with bnClick2: IE5.5 or higher (I'm not sure )
with bnClick3: IE4.0 or Netscape 4.0 or higher( not sure )
you can goes http://webreference.com/js/tutorial1/ to look your code which you want
Good luck