function isEmailAddress(valor)
	{
		if (/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,3})+$/.test(valor)){
			return (true)
		} else {
			return (false);
		}
	}

	function valida_nif_cif_nie(cf) {
		cf = cf.toUpperCase();
		var num = new Array(9);
		for (var i = 0; i < 9; i++){
			num[i] = cf.substr(i,1);
		}

		//si no tiene un formato valido devuelve error
		var re = /((^[A-Z]{1}[0-9]{7}[A-Z0-9]{1}$|^[T]{1}[A-Z0-9]{8}$)|^[0-9]{8}[A-Z]{1}$)/;
		if(!re.test(cf)) return 0;

		//comprobacion de NIFs estandar
		re = /(^[0-9]{8}[A-Z]{1}$)/;
		if(re.test(cf)){
			var pat = 'TRWAGMYFPDXBNJZSQVHLCKE';
			if(num[8] == pat.substr(cf.substr(0,8) % 23, 1)) return 1;
			else return -1;
		}

		//algoritmo para comprobacion de codigos tipo CIF
		var suma = parseInt(num[2]) + parseInt(num[4]) + parseInt(num[6]);
		var tmp;

		for (var i = 1; i < 8; i += 2){
			tmp = 2 * num[i];
			suma += parseInt(String(tmp).substr(0,1));
			if(parseInt(String(tmp).substr(1,1))){
				suma += parseInt(String(tmp).substr(1,1));
			}
		}
		var n = 10 - parseInt(String(suma).substr(String(suma).length - 1, 1))

		//comprobacion de NIFs especiales (se calculan como CIFs)
		re = /^[KLM]{1}/;
		if(re.test(cf)){
			if(num[8] == String.fromCharCode(parseInt(64 + n))) return 1;
			else return -1;
		}

		//comprobacion de CIFs
		re = /^[ABCDEFGHNPQS]{1}/;
		if(re.test(cf)){
			if(num[8] == String.fromCharCode(parseInt(64 + n)) || num[8] == String(n).substr(String(n).length -1, 1) ) return 2;
			else return -2;
		}

		//comprobacion de NIEs
		re = /^[TX]{1}/;
		var re2 = /^[T]{1}[A-Z0-9]{8}$/;
		var re3 = /X/;
		var strTmp = 'TRWAGMYFPDXBNJZSQVHLCKE';
		if(re.test(cf)){
			tmp = cf.replace(re3,'0');
			tmp = tmp.substr(0,8)%23;
			tmp = strTmp.substr(tmp,1);
			if(num[8] == tmp || re2.test(cf) ) return 3;
			else return -3;
		}

		//si todavia no se ha verificado devuelve error
		return 0;
	}
	
	function esEnteroPositivo(str){
		var re = /^([0-9]+)$/;
		if(re.test(str)) return true;
		return false;
	}
	
	function recorta(str){
		return str.replace(/^(\s*)((\s*\S+)*)(\s*)$/,"$2");
	}
	
	function textoVacio(texto){
		if ((texto == null) || (texto.length == 0))	return true;
		if (texto.search(/\S+/) != -1) return false;
		return true;
	}