/*********************************************************/
/* VALIDA E-MAIL */
function checa_mail(mail){
	var str, arroba, ponto
	str=mail
	for (i=0; i < (mail.length-1); i++){
		if ((i > 0) && (str.charAt(i)=="@")) {
			arroba=true
		} else
			if ((str.charAt(i)==".") && (arroba)) {
				ponto=true
			}
	}
	if ((! arroba) || (! ponto))
		return false
	else
		return true
}

/** MOSTRA E ESCONDE DIVS **/

function getStyle(id){	
	return document.getElementById(id).style;
}

function HideLayer(id){	
	getStyle(id).visibility = "hidden";
	getStyle(id).display = "none";
}
function ShowLayer(id){	
	getStyle(id).visibility = "visible";
	getStyle(id).display = "block";
}

/**  ROLL OVER DE IMAGENS **/
function roll(img_name, img_src){
   document[img_name].src = img_src;
}

/*******************************************************************************/

function disableFields(a, b, c){
	if (document.getElementById(a).style.visibility == "visible"){
		document.getElementById(a).style.visibility = "hidden";
		document.getElementById(b).style.visibility = "hidden";
		document.getElementById(c).style.visibility = "hidden";
	}else{
		document.getElementById(a).style.visibility = "visible";
		document.getElementById(b).style.visibility = "visible";
		document.getElementById(c).style.visibility = "visible";
	}
}