Open new window when button click within updatepanel

protected void printbtn_Click(object sender, ImageClickEventArgs e)
{
 StringBuilder sb = new StringBuilder();
 sb.Append("<script>");
 sb.Append("window.open('"+path+"', '', '');");
 sb.Append("</script>")
 ScriptManager.RegisterStartupScript(this, this.Page.GetType(), "test", sb.ToString(), false);
}