var banner=new Array()
banner[0]='<a href="/signup.php"><img src="images/matri-hp-img-1.jpg" width="254" height="209" border="0"></a>'
banner[1]='<a href="/signup.php"><img src="images/matri-hp-img-2.jpg" width="254" height="209" border="0"></a>'
banner[2]='<a href="/signup.php"><img src="images/matri-hp-img-3.jpg" width="254" height="209" border="0"></a>'
banner[3]='<a href="/signup.php"><img src="images/matri-hp-img-4.jpg" width="254" height="209" border="0"></a>'
var whichbanner=Math.floor(Math.random()*(banner.length))
document.write(banner[whichbanner])