aspx c# open new window in button click event when the button is placed inside an ajax update panel

val1 is an integer
val2 is a boolean

System.Text.StringBuilder sb = new System.Text.StringBuilder();
sb.Append("window.open(abc.aspx?val1=" + val1Value.ToString() + "');");
ScriptManager.RegisterClientScriptBlock(this.upd1, this.upd1.GetType(), "abc", sb.ToString(), true);