How to post back to a particular page using JavaScript

I am using Asp.net with Java Script.

I have a java script method in my master page named "search".
When search is called I display a popup window. When that window
closes, I would like to transfer the user to a specific Asp.net
page. Let's call that page "default.aspx"

So how do I transfer to the default.aspx page using Java script? This
would probably be done at line 6 below, but I don't know how to do it.

Note that if search is performed 50 times, I don't want 50 default.apx
windows open. I just want one default.aspx window open.

So somehow I need to always post back to "default.aspx"


1  <script type="text/javascript">
2
3 function search()
4 {
5      window.showModalDialog("PopupPage.aspx")


6
7}
8</script>