function changeFront(pic_name)
{
	var pic = 'images/products/' + pic_name;
	document.getElementById('front').src = "images/sel_front.gif";
	document.getElementById('back').src = "images/back.gif";
	document.getElementById('big_pic').src = pic;		
}

function changeBack(pic_name)
{
	var pic = 'images/products/' + pic_name;
	document.getElementById('front').src = "images/front.gif";
	document.getElementById('back').src = "images/sel_back.gif";
	document.getElementById('big_pic').src = pic;	
}