var bana = [['http://www.wabao.com/fanli/', '1270203461.jpg'],['http://www.wabao.com/fanli/', '1270203422.jpg'],['http://www.wabao.com/', '1270203382.jpg'],['http://www.wabao.com/sales/', '1270203333.jpg']];
var rban = Math.floor(Math.random() * 4);