function imgOn(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + 'on.src');
	}
}

function imgOff(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + 'off.src');
	}
}

function imgOnsel(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + 'sel.src');
	}
}

function imgOffsel(imgName) {
	if (document.images) {
		document[imgName].src = eval(imgName + 'sel.src');
	}
}

function view_ad(num){
	document.ad_large.src = 'images/'+num+'.jpg';
	current_ad = num;
}