function OpenCenterPopUp(url, aWidth, aHeight) {
if(!aWidth) {
var aWidth = 760;
}
if(!aHeight) {
var aHeight = 420;
}
var Left=(window.screen.width/2)-(aWidth/2);
var Top=(window.screen.height/2)-(aHeight/2);
var Configuration='scrollbars=yes, resizable=yes, width='+aWidth+', height='+aHeight+', top='+Top+', left='+Left;
var f = window.open(url,'print',Configuration);
f.focus();
}