function swap( F, R )
{
  var vD = F.defaultValue;
  if ( F.value == ( R ? '' : vD ) ) F.value = ( R ? vD : '' );
}

matchZIP.known = null;
function matchZIP( F )
{
  if ( !matchZIP.known )  return false;
  else
  {
    var zip = F.elements[ 'zip' ].value;

    if ( !matchZIP.known[ zip ] ) zip = '00000';  // '00000' == statewide
    F.action = '/endorsement/search/' + zip + '.html';

    return true;
  }
}