// JavaScript Document
function changeImage()
{

	var div=document.getElementById('header_main');
	
		var noOfImages=12;
		var randomnumber=Math.floor(Math.random()*noOfImages);
		
		switch(randomnumber)
{
case 0:
  div.style.background="url(images/topimage.jpg) no-repeat";
  break;
case 1:
  div.style.background="url(images/image.jpg) no-repeat";
  break;
case 2:
  div.style.background="url(images/image2.jpg) no-repeat";
  break;
case 3:
  div.style.background="url(images/image3.jpg) no-repeat";
  break;
case 4:
  div.style.background="url(images/image4.jpg) no-repeat";
  break;
case 5:
  div.style.background="url(images/image5.jpg) no-repeat";
  break;
case 6:
  div.style.background="url(images/h1.jpg) no-repeat";
  break;
case 7:
  div.style.background="url(images/h2.jpg) no-repeat";
  break;
case 8:
  div.style.background="url(images/h3.jpg) no-repeat";
  break;
case 9:
  div.style.background="url(images/h4.jpg) no-repeat";
  break;
case 10:
  div.style.background="url(images/h5.jpg) no-repeat";
  break;
case 11:
  div.style.background="url(images/h6.jpg) no-repeat";
  break;
case 12:
  div.style.background="url(images/h7.jpg) no-repeat";
  break;
default:
div.style.background="url(images/topimage.jpg) no-repeat";
}
		div.style.height="261px";
		div.style.width="760px";
		div.style.fload="left";
		
}