function getImage()
{
	var image=new Array(6);
	image[0]="Batman";
	image[1]="Supes";
	image[2]="Kitty";
	image[3]="Hellboy";
	image[4]="Cw";
	image[5]="Cap";
	document.getElementById('header').style.backgroundImage="url('_img/bgHeader" + image[Math.floor(Math.random()*6)]+ ".gif')";	
}