if (document.images) {
	cat_on =new Image();  cat_on.src ="selector/sel_cat_on.png"; 
	cat_off=new Image();  cat_off.src="selector/sel_cat.png"; 
	cas_on =new Image();  cas_on.src ="selector/sel_cas_on.png"; 
	cas_off=new Image();  cas_off.src="selector/sel_cas.png"; 
}

function handleOver() { 
	if (document.images) document.cat.src = cat_on.src;
}

function handleOut() {
	if (document.images) document.cat.src = cat_off.src;
}

function handleOverCas() { 
	if (document.images) document.cas.src = cas_on.src;
}

function handleOutCas() {
	if (document.images) document.cas.src = cas_off.src;
}