Clear browser history

//clears browser history and redirects url
<SCRIPT LANGUAGE=javascript> {  var Backlen=history.length;   history.go(-Backlen);   window.location.href=page url }</SCRIPT>

Page.ClientScript.RegisterStartupScript(this.GetType(),"cle","windows.history.clear",true);

protected void LogOut()   
{       
     Session.Abandon();       
     string nextpage = "Logoutt.aspx";       
     Response.Write("<script language=javascript>");             
     Response.Write("{");       
     Response.Write(" var Backlen=history.length;");       
     Response.Write(" history.go(-Backlen);");       
     Response.Write(" window.location.href='" + nextpage + "'; ");
     Response.Write("}");       
     Response.Write("</script>");   
}