function changeFundo(x){
	var a=document.getElementById('fundo');
	for (n=0;n<13;n++){
		document.getElementsByTagName('span')[n].style.color="black";
		}
	  
	    a.src="/files/teste/teste"+x+".jpg";
	    if (x=0)  a.src="";
	    document.getElementsByTagName('span')[x-1].style.color="red";
}