function addLoadEvent(func) {
	var oldonload=window.onload;
	if(typeof window.onload != 'function') {
		window.onload=func;
	}else{
		window.onload=function() {
			oldonload();
			func();
		}
	}
}

function isFilled(field) {
	if(field.value.length<1 || field.value == field.defaultValue) {
		return false;
	}else{
		return true;
}}

function isEmail(field) {
	if(field.value.indexOf("@")==-1 || field.value.indexOf(".") ==-1) {
		return false;
	}else{
		return true;
}}

function validateForm(whichform){
	for (var i=0;i<whichform.elements.length;i++) {
		var element=whichform.elements[i];
		if(element.className.indexOf("required") != -1){
			if(!isFilled(element)) {
				alert("Por favor rellene el campo "+element.name+".");
				return false;
		}
	}
	if(element.className.indexOf("email") != -1) {
		if(!isEmail(element)){
			alert ("El campo "+element.name+" debe ser una dirección válida de email");
			return false;
	}}}
	return true;
}

function prepareForms() {
	for (var i=0;i<document.forms.length;i++){
		var thisform=document.forms[i];
		resetFields(thisform);
		thisform.onsubmit=function() {
			return validateForm(this);
		}
	}
}

function resetFields(whichform) {
	for (var i=0;i<whichform.elements.length;i++){
		var element=whichform.elements[i];
		if(element.type=="submit") continue;
		if(element.type=="hidden") continue;
		if(!element.defaultValue) continue;
		element.onfocus=function(){
			if(this.value==this.defaultValue) {
			this.className="border_orange";
			this.value="";
			
		}
		}
		element.onblur=function() {
			if(this.value==""){
			this.className="no_border";
			this.value=this.defaultValue;
			
}}}}


function focusLabels(){
	if(!document.getElementsByTagName) return false;
	var labels=document.getElementsByTagName("label");
	for(var i=0;i<labels.length;i++){
		if(!labels[i].getAttribute("for")) continue;
		labels[i].onclick=function() {
			var id=this.getAttribute("for");
			if(!document.getElementById(id)) return false;
			var element = document.getElementById(id);
			element.focus();
}}}

addLoadEvent(focusLabels);
addLoadEvent(prepareForms);