var images = new Array();

images[0] =  "images/header/banner_01.jpg";
images[1] =  "images/header/banner_02.jpg";
images[2] =  "images/header/banner_03.jpg";
images[3] =  "images/header/banner_04.jpg";





function ShowImg() {
var number = images.length;
var increment = Math.floor(Math.random() * number);
var strTemp ='<img src="../' + images[increment] + '">';
document.write(strTemp);
}