onclick of you button write
if (System.IO.File.Exists(outputFilenameSCMS))
{
Response.Redirect(
"Overview.aspx?UserID=" + UserID + "&FileName1=" + outputFilenameSCMS);
}
then on page_load of the overview page, like u were saying take the file value from the query string and
if (System.IO.File.Exists(outputFilenameSCMS))
{
Response.ClearHeaders();
Response.ClearContent();
Response.AddHeader("Content-Disposition", "attachment; filename= " + filename1);
Response.WriteFile(outputFilenameSCMS, true);
Response.End();
}
HC