HELP how to a pass datagrid value from one window to textbox field in another window

[savoym]

I just inherited a VB.NET web project and I have what is hopefully a quick answer question.

The developer used an "a href" tag to open a new window where there is a datagrid of 2 columns in this 2nd window. I set the first column in the datagrid to a hyperlinkcolumn in the ASP.NET side of the datagrid in the second window and I have set the value of that datagrid in the hyperlink. I want to be able to acquire the value from that selected record when I click the hyperlink, close the 2nd window and populate a textbox in the first window with the value acquired from the datagrid in the 2nd window.

ANY suggestions/direction would be greatly appreciated.