var btn;
var imag;
function sobre(btn, imag){
document.images[btn].src= imag;
		}
function fuera(btn, imag){
document.images[btn].src= imag;
		}



function preCarga() {
if (!document.images) return;
var ar = new Array();
var arguments = preload.arguments;
for (var i = 0; i < arguments.length; i++) {
ar[i] = new Image();
ar[i].src = arguments[i];
}
}

var f_cual;
var f_img;
function sobre_mas(f_cual, f_img){
document.getElementById(f_cual).className=f_img; 
		}
function fuera_mas(f_cual, f_img){
document.getElementById(f_cual).className=f_img; 
		}