function popupLarge(){
 var x=440;
 var y=425;
 var xPos = Math.round( (screen.width/2) - (x/2) ) + 80;
 var yPos = Math.round( (screen.height/2) - (y/2) );
 var winIntro =
 window.open('','popup','location=no,menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=' + x + ',height=' + y + ',left=' + xPos + ',top=' +yPos + ',screenX=' + xPos + ',screenY=' + yPos, true);
 }

 function popupMedium(){
 var x=355;
 var y=395;
 var xPos = Math.round( (screen.width/2) - (x/2) ) + 80;
 var yPos = Math.round( (screen.height/2) - (y/2) );
 var winIntro =
 window.open('','popup','location=no,menubar=no,toolbar=no,resizable=yes,scrollbars=yes,width=' + x + ',height=' + y + ',left=' + xPos + ',top=' +yPos + ',screenX=' + xPos + ',screenY=' + yPos, true);
 }