I agree with the comment to the question by Homero Rivera. Please see my recent answer where I explain why popup windows are bad and suggest some useful alternatives:
Problem in firefox popup windows for web base ASP.NET application[
^].
But I don't say that the "modal popup" solution is necessarily what you need. Some other solution which simply change the layout to show some detail on some event ("drill-down") on the same page can be beneficial. For example, you could keep required grid view or its part hidden (presumably "collapsed") until it is needed for a "drill-down" event. Then you can show this element by either moving or hiding other elements or by superimposing it on top. There are numerous designs like that, and some of them are even user-friendly. :-)
—SA