function centerPopup(windowWidth,windowHeight , windowName, windowUri)
{
    var centerWidth = (window.screen.width - windowWidth) / 2;
    var centerHeight = (window.screen.height - windowHeight) / 2;
    var win = window.open(windowUri, windowName, 'menubar=0,location=0,directories=0,scrollbars=0,resizable=0,toolbar=0,status=0,width=' + windowWidth + 
        ',height=' + windowHeight + 
        ',left=' + centerWidth + 
        
        ',top=' + centerHeight);

    win.focus();
    return win.name;
}