function hide_all_media_forms() {
	$('#upload form .media_submission_form').each(function() {
			var parent = $(this).parent().get(0);
			$(parent).hide()
		});
}

$(document).ready(function() {
		$('#field_media_type select').change(function() {
				hide_all_media_forms();
				$('#field_media_type select option:selected').each(function() {
						$('#' + $(this).val() + '_form').show();
					});
			});
	});