myWin = null;

function openWin(x,y,url)
{
 var width = x;
 var height = y;
 var page = url.toString();
 var options = "resizable=0,width="+width.toString();
 options += ",height="+height.toString();
 var leftborder = Math.ceil((screen.availWidth-width)/2);
 var topborder = Math.ceil((screen.availHeight-height)/2);
 options += ",left="+leftborder.toString();
 options += ",top="+topborder.toString();
 options += ",scrollbars=1";

 myWin = window.open(page,"myWin",options)
 myWin.focus();
}


function closeWin()
{
 if (myWin != null)
 if (!myWin.closed)
 myWin.close();
}