function swap() {
var numimages=10;
rndimg = new Array
("../imgs/left_id.jpg","../imgs/left_id1.jpg", "../imgs/left_id2.jpg", 
"../imgs/left_id3.jpg", "../imgs/left_id4.jpg","../imgs/left_id5.jpg", "../imgs/left_id6.jpg",
"../imgs/left_id7.jpg", "../imgs/left_id8.jpg","../imgs/left_id9.jpg");
rndimg1 = new Array
("../imgs/middle_id.jpg", "../imgs/middle_id0.jpg","../imgs/middle_id1.jpg", "../imgs/middle_id2.jpg", 
"../imgs/middle_id3.jpg", "../imgs/middle_id4.jpg","../imgs/middle_id5.jpg", 
"../imgs/middle_id7.jpg", "../imgs/middle_id8.jpg","../imgs/middle_id9.jpg");
rndimg2 = new Array
("../imgs/right.jpg", "../imgs/right0.jpg","../imgs/right1.jpg", "../imgs/right2.jpg", 
"../imgs/right3.jpg", "../imgs/right4.jpg","../imgs/right5.jpg", "../imgs/right6.jpg",
"../imgs/right7.jpg", "../imgs/right8.jpg");
x=(Math.floor(Math.random()*numimages));
x1=(Math.floor(Math.random()*numimages));
x2=(Math.floor(Math.random()*numimages));
randomimage=(rndimg[x]);
randomimage1=(rndimg1[x1]);
randomimage2=(rndimg2[x2]);
document.getElementById("imgLeftid").style.backgroundImage = "url("+ randomimage +")"; 
document.getElementById("imgMiddleid").style.backgroundImage = "url("+ randomimage1 +")";
document.getElementById("imgRightid").style.backgroundImage = "url("+ randomimage2 +")"; 
}
if (document.getElementById) { window.onload = swap };
//-->