Below is what I'm currently doing but it redirects the popup window not open a new tab on the parent window.
Protected Sub btnFullRecord_Click(sender As Object, e As EventArgs) Dim TRAINEEID = Session("TRAINEEID") Dim POT = Session("POT") Response.Redirect([String].Format("candidategeneral.aspx?TraineeID={0}&POT={1}", TRAINEEID, POT)) End Sub