function header(tag, src, TotalPic, timeout) {
name = tag;
timeoutid ="";
headers = new Array(TotalPic);	
		for (i=0;i<TotalPic;i++){
			headers[i] = new Image();
			headers[i].src = src + '-0' + (i+1) + '.jpg';//create images array with preload
			}
			

function next() {
	var random = Math.floor(Math.random()* TotalPic);
	var newImage = 'url('+ headers[random].src +')';

	document.getElementById(name).style.backgroundImage = newImage;
	
}
this.next = function(){ next();}


this.loop = function(){
	this.next();
	timeoutid = setInterval(next, timeout);
	}


}//end header