window.addEvent('domready', function() {
	var defaultRowDisplay = (document.getElement('tr').getStyle('display'));
	var formTypeDropdown = $('contact_form_type');
	if (formTypeDropdown) {
		var showHideFields = function() {
			var selectedOption = formTypeDropdown.get('value');
			$$('.contact_form_field_form').each(function(fieldForm) {
				var toShowOrHide = fieldForm.getParent('tr');
				if (fieldForm.hasClass(selectedOption)) {
					toShowOrHide.setStyle('display', defaultRowDisplay);
				} else {
					toShowOrHide.setStyle('display', 'none');
				}
			});
		}
		formTypeDropdown.addEvent('change', showHideFields);
		formTypeDropdown.addEvent('keydown', showHideFields);
		showHideFields();
	}
});