bgslider = function(el, scrollwidth, width, dir){
	this.constructor(el, scrollwidth, width, dir);
}
bgslider.prototype = {
	el:null,
	dir: -1,
	pos: 0,
	sw: 0,
	w: 0,
	start:0,
	end:0,
	timer:null,
	constructor : function(el, sw, w, dir) {
		var t = this;
		t.el = document.getElementById(el);
		t.el.innerHTML += t.el.innerHTML;
		t.dir = dir == -1 ? -1 : 1;

		t.el.style.width = (2 * sw) + 'px';
		if(t.dir == -1) {
			t.start = -1 * ((sw  * 2) - w);
			t.end = t.start + sw;
		} else {
			t.start = 0;
			t.end = -1 * sw;
		}
		t.pos = t.start;
		t.el.style.left = t.start + "px";
		t.timer = window.setInterval(function(){t.scroll()}, 40);
	},
	scroll: function(){
		this.pos -= 1 * this.dir;

		if(this.pos == this.end) {
			this.pos = this.start;
		}

		this.el.style.left = this.pos+"px";
	}
}