images = new Array(18); images[0] = "images/header1.jpg"; images[1] = "images/header2.jpg"; images[2] = "images/header3.jpg"; images[3] = "images/header4.jpg"; images[4] = "images/header5.jpg"; images[5] = "images/header6.jpg"; images[6] = "images/header7.jpg"; images[7] = "images/header8.jpg"; images[8] = "images/header9.jpg"; images[9] = "images/header10.jpg"; images[10] = "images/header11.jpg"; images[11] = "images/header12.jpg"; images[12] = "images/header13.jpg"; images[13] = "images/header14.jpg"; images[14] = "images/header15.jpg"; images[15] = "images/header16.jpg"; images[16] = "images/header17.jpg"; images[17] = "images/header18.jpg"; function rotate() { randNum = Math.floor(Math.random()*18); document.getElementById("leftcontainer").style.backgroundImage = "url("+images[randNum]+")"; }