ASP/VB logic problem

I have a page that I have created with a gridview.

I am taking the values from a column and creating a URL out of them.
I have a button on the page that, when clicked, should open a new browser window with the URL I created in the page.

I have tried this a few different ways with out much success. If I place the URL builder in the ASP page, I don't seem to be able to call the sub automatically so that the URL is built before the user clicks on a button.

If I set the button to run the sub, I can't get a new window opened with the URL from the sub.

If I move all of the vb to the asp.vb page in the onload event, it no longer can see the gridview to build my URL.

Here is what I have at the moment, the page renders but I am missing a way to navigate to the URL....

[code]

<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default.aspx.vb" Inherits="_Default" %>