// Open popup windows / popup Dialog
function popupWindow(url,args,w,h,flag){    
    var topPosition = (screen.height) ? (screen.height-h)/2 : 0;
    var leftPosition = (screen.width) ? (screen.width-w)/2 : 0;
    var settings = 'left='+leftPosition+',top='+topPosition+',resizable=no,scrollbars=no,width='+w+',height='+h+',toolbar=no';
    
    if(flag == true){
        var result = window.showModalDialog(url,args,"center:yes;help:no;status:no;dialogWidth:"+w+"px;dialogHeight:"+h+"px");
    }else{
        var result = window.open(url,"",settings,true);
    }    
    
    return result;
}