GiveFocus(this.TextBox1); publicvoid GiveFocus(Control c) { RegisterClientScriptBlock("CSP-focus-function", "<script language=\"JavaScript\"> function CSP_focus(id) { var o = document.getElementById(id); if (o != null) o.focus(); }</script>"); RegisterStartupScript("CSP-focus", "<script language=\"JavaScript\">CSP_focus('"+ c.ClientID +"');</script>"); }