function toggle(obj) {document.getElementById(obj).style.display=(document.getElementById(obj).style.display!="block")? "block" : "none";} 

var win = null;
var myname = "popup";
var w = (screen.width)/1.5;
var h = (screen.height)/2;
var scr = "no";

function pop(mypage,scr){
leftposition = (screen.width) ? (screen.width-w)/2 : 0;
topposition = (screen.height) ? (screen.height-h)/2 : 0;
//settings ='height='+h+',width='+w+',top='+topposition+',left='+leftposition+',scrollbars='+scr+',resizable=yes,directories=no,location=yes,menubar=no,status=no,toolbar=no';
settings ='height='+h+',width='+w+',top='+topposition+',left='+leftposition+',scrollbars=yes,resizable=yes,directories=no,location=yes,menubar=yes,status=no,toolbar=no';
win = window.open(mypage,myname,settings);
}