var mess = new Array(
'<img height="517" alt="Glass Ceiling" src="images/random/glassceilingemployer.gif" width="346" border="0">',
'<img height="425" alt="Not just a Job" src="images/random/setscheduleemployer.gif" width="349" border="0">');
var max = mess.length;
var num = Math.floor((Math.random() * max));
document.writeln(mess[num]);