private function isRequired($field, $value) {
		
		if(true === isset($this -> required[$field])) {
			
			$empty = true;

			if(true === is_array($value)) {

				foreach($value as $val) {

					if(strlen(trim($val)) > 0) {
						$empty = false;
					}
				}
			}

			if(true === is_string($value) && strlen(trim($value)) > 0) {
				$empty = false;
			}

			if(false === $this -> required[$field] && $empty) {
			    return true;
			}
		}

		return false;
	}