function popwin( url, w, h ) {
    var left = (screen.width - w) / 2;
    var top = (screen.height - h) /2 ; 
    var prop = "dependent=yes, width="+w+", height="+h+", left="+left+", top="+top+", resizable=yes, scrollbars=yes, menubar=no, statusbar=no, toolbar=no, location=no";
    var product = window.open(url, name, prop);
}

function productswrap( link, w, h ) { 
    document.images['productimage'].src=link;
    //document.getElementById('imglink').onclick=popwin(link, w, h);
    document.getElementById('imglink').onclick = function() {
     popwin( link, w+50, h+50 );
    }
}