function sw(obj){

if ( document.getElementById ){
		if (document.getElementById(obj).style.visibility=='hidden') {
			document.getElementById(obj).style.visibility=''
		} else {
			document.getElementById(obj).style.visibility='hidden'
		}
	}
}

function xc(obj){
if ( document.getElementById ){
		if ( document.getElementById(obj).style.backgroundImage == "url("+obj+".png)" ) {
			document.getElementById(obj).style.backgroundImage = "url("+obj+"-over.png)"
		} else {
			document.getElementById(obj).style.backgroundImage = "url("+obj+".png)"
		}
	}
}

function st(file){
	document.map_main.src=file+".png";
	document.map_over.src=file+"-over.png";
}