function obre_logo() {
	var elm=document.getElementById("flash");
	elm.style.visibility="hidden";
	elm.style.width="900px";
	elm.style.height="650px";
	elm.style.top="0px";
	elm.style.visibility="visible";
}
function tanca_logo() {
	var elm=document.getElementById("flash");
	elm.style.width="170px";
	elm.style.height="162px";
	elm.style.top="488px";
}