function form_validator(formobj) {

	this.form = formobj;
	this.elementos = new Array;
	this.alert = true;
	
	this.add = function (nombre,validator,error_str) {
		if ((nombre) && (validator)) {
			this.elementos[nombre] = new Array;
			this.elementos[nombre]['error_str'] = (error_str)?error_str:'';
			this.elementos[nombre]['validator'] = validator;
		}
	}
	
	this.validate = function () {
		var error = false;
		if ((this.form) && (this.elementos)) {
			for (var i in this.elementos) {
				var value = getFormControlValue(this.form[i]);
				var tipo_chequeo = this.elementos[i]['validator'];
				var chequeo_arr = tipo_chequeo.split("-");
				tipo_chequeo = chequeo_arr[0];
				switch (tipo_chequeo) {
					case 'req':
						error = (is_empty(value)) ;
					break;
					case 'email':
						error = (!is_email(value));
					break;
					case 'numeric':
						error = (!is_numeric(value));
					break;
					case 'date':
						error = (!is_date(value));
					break;
					case 'max':
						error = (!maxlength(value,parseInt(chequeo_arr[1])));
					break;
					case 'min':
						error = (!minlength(value,parseInt(chequeo_arr[1])));
					break;
				}
				if (error) {
					error_str = this.elementos[i]['error_str'];
					error_obj = this.form[i];
					break;
				}
			}
			if (error) {
				if (this.alert) {
					alert(this.alert_before_str+error_str+this.alert_after_str);
				}
				if ((error_obj)&&(error_obj.focus))
					error_obj.focus();
			}
			return (!error);
		} else {
			alert ('Error en la validación de los datos');
			return false;
		}
	}
	
	this.setAlert = function(value,before_str,after_str) {
		this.alert=value;
		this.alert_before_str = (before_str)?before_str:'';
		this.alert_after_str = (after_str)?after_str:'';
	}
	
	return this;
}

function getFormControlValue(element) {
	if (element && element.type) {
		switch (element.type) {
			case 'checkbox':
				return (element.checked)?element.value:false;
			break;
			case 'text':
			case 'textarea':
			case 'select-one':
			default:
				return element.value;
			break;
		}
	} else if (element && element.length) {
		for (i=0;i<element.length;i++) {
			if (element[i].checked==true) {
				return element[i].value;
			}
		}
	}
	return false;
}