/**
  * Updates the value and disabled state of the input field 'dealers[zip]'
  * depending on the selection of dealers[country][uid].
  *
  * @param	object	element handle of the select tag with the
  * 				id 'dealers_country_select'
  */
function dealers_countryChanged(selectElement) {
	if (selectElement.getProperty('value') == '') {
		$('dealers_dealer_zip').setProperty('value', '');
		$('dealers_dealer_zip').setProperty('disabled', 'disabled');
	} else {
		$('dealers_dealer_zip').setProperty('disabled', '');
	}
}