function showPropertyPopup(url) {
	//var centerLeft = (screen.width - width) / 2;
	//var centerTop =  (screen.height - height) / 2;
	//Utilizamos una expresión regular en el 2º parámetro del método window.open para eliminar los caracteres no alfanuméricos.
	//popup = window.open(url, url.split('.')[0].replace(/[^\w@-]/g, ''), 'width=' + width + ',height=' + height + ',resizable=0,left=' + centerLeft + ',top=' + centerTop);
	popup = window.open(url, url.split('.')[0].replace(/[^\w@]/g, ''), 'resizable=1,scrollbars=yes');    
	//popup.moveTo(centerLeft, centerTop);
	return popup;
}

//Sólo admite fechas válidas con el formato dd/mm/aaaa.
//Valida años bisiestos.
function isDate(value) {
	var regExp = /^(?:(?:0?[1-9]|1\d|2[0-8])(\/|-)(?:0?[1-9]|1[0-2]))(\/|-)(?:[1-9]\d\d\d|\d[1-9]\d\d|\d\d[1-9]\d|\d\d\d[1-9])$|^(?:(?:31(\/|-)(?:0?[13578]|1[02]))|(?:(?:29|30)(\/|-)(?:0?[1,3-9]|1[0-2])))(\/|-)(?:[1-9]\d\d\d|\d[1-9]\d\d|\d\d[1-9]\d|\d\d\d[1-9])$|^(29(\/|-)0?2)(\/|-)(?:(?:0[48]00|[13579][26]00|[2468][048]00)|(?:\d\d)?(?:0[48]|[2468][048]|[13579][26]))$/;
	return regExp.test(value);
}

//Sólo admite números enteros positivos o negativos.
function isNumber(value) {
	var regExp = /(^-?\d\d*$)/;
	return regExp.test(value);
}

function isImage(value) {
	if (value != '') {
		extension = value.substr(value.lastIndexOf('.') + 1).toLowerCase();
		return (extension == 'jpg') ||(extension == 'gif') || (extension == 'jpeg') || (extension == 'png');
	} else {
		return false;
	}
}

//Sólo admite direcciones de correo electrónico válidas
function isEmail(value) {
	var regExp = /^([a-zA-Z0-9_\-])([a-zA-Z0-9_\-\.]*)@(\[((25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\.){3}|((([a-zA-Z0-9\-]+)\.)+))([a-zA-Z]{2,}|(25[0-5]|2[0-4][0-9]|1[0-9][0-9]|[1-9][0-9]|[0-9])\])$/;
  return regExp.test(value);
}