code: function( value, element, param ) {
  			// check if dependency is met
  			if ( !this.depend(param, element) ) {
  				return "dependency-mismatch";
  			}
  			if ( element.nodeName.toLowerCase() === "select" ) {
  				// could be an array for select-multiple or a string, both are fine this way
  				var val = $(element).val();
  				return val && val.length > 0;
  			}
  			if ( this.checkable(element) ) {
  				return this.getLength(value, element) > 0;
  			}
  			return $.trim(value).length > 0;
  		}
docs: http://jqueryvalidation.org/required-method/