gistfile1.php

<?php
//bp-xprofile/admin/js/admin.js

function hide( id ) {
	if ( !document.getElementById( id ) ) return false;

	document.getElementById( id ).style.display = "none";
	// the field id is [fieldtype]option[iterator] and not [fieldtype]div[iterator]
	field_id = id.replace( 'div', 'option' ); 
	document.getElementById( field_id ).value = '';
}