How to select text on modal popup windows in asp.net

Hi
I open modal popup windows using java script in asp.net.

function OpenChild()
{
var WinSettings= "resizable=no;dialogWidth:510px;dialogHeight:350px;help:no;maximize:yes;minimize:yes;scrollbars:yes";
var MyArgs = window.showModalDialog("http://localhost/Test/Test.aspx",WinSettings );

}

<input id="Button2" type="button" onclick="OpenChild();" value="button" />
Popup window is open well. But, there is lot of text on Test.aspx. Now, I want to select text for copy. But text is not selected.  I would like to know that how to select text and right click of mouse on modal popup?
If, is there alternative way to do this please tell me.
Any help is appreciated.
Regards
Rajesh