var n = Math.round(((img.length)-1) * Math.random()); 
document.write("<div align=center><a href="+ url[n] +" target=_Blank onMouseOver=\"window.status='"+ txt[n].replace(/\'/, "\\\'") +"'; return true; \" onMouseOut=\"window.status=''; return true;\"><img src="+ img[n] +" border=1 width=468 height=60 class=\"img\"></a></div>");