function ChangeBgImg(imgs) {
	bdy[0].style.backgroundImage = 'url('+imgs+')';
}

function ChangeBgImgInit() {
	bdy = document.getElementsByTagName("html");
	bdy[0].style.width = "100%";
	bdy[0].style.height = "100%";
	bdy[0].style.margin = "0px";
	bdy[0].style.backgroundImage = 'url(http://www.tarekshalaby.com/wp-content/themes/tarekshalaby/images/backgrounds/blue.jpg)';
}

onload=ChangeBgImgInit;