how open a popup window at button click in csharp

<script language="JavaScript"><!--
var windowHandle = null;
var windowHandle_closed = false;
 
function openWindow() {
    windowHandle = window.open('SearchPR.aspx','_blank','width=600,height=380,title=yes,toolbar=no,location=no,resizable=no,status=no');
    if (windowHandle_closed) {
        windowHandle_closed = false;
    }
}
 
function closeWindow() {
    if (windowHandle != null) {
        if (!windowHandle_closed) {
            windowHandle_closed = true;
            windowHandle.close();
        }
    }
}
//--></script>