Pass Asp:Textbox value to report URL parameter & make texbox hidden

Good day, I again need help - Yesterday I needed to pass the value to my Page2.
I want to pass that value to my report parameter (URL)
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>  
<script runat="server">  
protected void Page_Load(object sender, EventArgs e)  
{  
  if (Session["mytext"] != null)  
  {  
    TextBox2.Text = Session["mytext"].ToString();  
  }  
}  
</script>
I have the value returned to my TextBox2, now i want to pass the value to my report url
<IFRAME id="frame1" src="http://biweb/Reportse ...