function openWindow(url, name) { 
                popupWin = window.open(url, name,'width=300,height=300,left=50,top=50')
}

function popup(filename){
var centerWidth=(screen.width/2)-(620/2);
var centerHeight=(screen.height/2)-(500/2);
window.open(filename,"","height=500,width=620,top="+centerHeight+",left="+centerWidth+",location=no,menubar=no,resizable=yes,scrollbars=yes,status=no,titlebar=no,toolbar=no,directories=no");
}