Response.Write And Window.open Issue

I have an asp and a page with two frames. (constant, main)
I would like to show the page on a different frame. (main)
Here is what I have:

I am working in C#


void MYSelectedChangeEventHandlerFunction(DropDownList DD)
{
try
{
string address = DD.SelectedItem.Value;
//Response.Redirect("address");
Response.Write(" <script> window.open(address,main); </script> ")
}
catch(Exception ex)
{
DD.Items.Add("Dir Errors Found!");
}

}

What AM I doing wrong? Is there a better way to out put the page to a different frame within the function.