function alerta(texto){
			document.getElementById('alerta').innerHTML = texto;
			document.getElementById('alerta').style.display ="block";
}

function valida() {

	
	var correcto = true;

		realname  = document.getElementById('realname');
		email     = document.getElementById('email');
		m2			 = document.getElementById('m2');

	if (realname.value == "" || realname.value == "Campo Obligatorio") {

		alerta ('Falta un nombre');
		realname.focus();
		correcto = false;
	}
	
	if (m2.value == "" || m2.value == "0") {

		alerta ('Valor incorrecto');
		m2.focus();
		correcto = false;
	}

	if (	(correcto) 
				&& 
			(email.value == "" || email.value.indexOf ('@', 0) == -1 || email.value.indexOf ('.', 0) == -1 || email.value == "@." || email.value == ".@" || email.value == " ") 
		) 
		{

      alerta ('E-mail incorrecto');
		email.focus();
		correcto = false;
	}
	
	if((correcto) && (isNaN(document.getElementById('m2').value))){
		alerta ('Metros incorrectos');
		m2.focus();
		correcto = false;
	}
	
if (correcto){

	document.getElementById('email').value = document.getElementById('email').value.toLowerCase();
	formulario.submit();
		}
}

function newImage(arg) {
	if (document.images) {
		rslt = new Image();
		rslt.src = arg;
		return rslt;
	}
}

function changeImages() {
	if (document.images && (preloadFlag == true)) {
		for (var i=0; i<changeImages.arguments.length; i+=2) {
			document[changeImages.arguments[i]].src = changeImages.arguments[i+1];
		}
	}
}

var preloadFlag = false;

function preloadImages() {
	if (document.images) {
		imgHome_home_over = newImage("../images/imgHome-home_over.jpg");
		imgEmpresa_empresa_over = newImage("../images/imgEmpresa-empresa_over.jpg");
		imgCasas_casas_over = newImage("../images/imgCasas-casas_over.jpg");
		imgOtros_otros__over = newImage("../images/imgOtros-otros-_over.jpg");
		imgIdeas_ideas_over = newImage("../images/imgIdeas-ideas_over.jpg");
		imgFaqs_faqs_over = newImage("../images/imgFaqs-faqs_over.jpg");
		imgenviar_over = newImage("../images/enviar_over.gif");
		imgenviar_off = newImage("../images/enviar_off.gif");
		imgenviar_down = newImage("../images/enviar_down.gif");
		imgContactar_contactar_over = newImage("../images/imgContactar-contactar_over.jpg");
		preloadFlag = true;
	}
}