var myPopupWindow = ''; 

function PopWin(url,name,width,height)
{
    //If it is already open   
    if (!myPopupWindow.closed && myPopupWindow.location)   
    {   
        myPopupWindow.close();   
    }   
    sleft = (screen.width-width)/2;
    stop = (screen.height-height)/2;
    myPopupWindow = window.open(url, "myPopupWindow", "location=no, scrollbars=no, resizable=no, toolbar=no, menubar=no, width=" + width + ", height=" + height + ", left=" + sleft + ", top= " + stop  );   
    if (!myPopupWindow.opener) myPopupWindow.opener = self;    
    if (window.focus) {myPopupWindow.focus()}
}
function ViewImage(imageUrl)
{
    window.open(imageUrl,'ImageViewer','toolbar=0,location=0,menubar=0');
}