trend_navigation.php

<?php
$months_ahead = array(0,1,2,3,6,9,12,18,24);
$months_back = array(12,9,6,3,2,1);
if ( !isset($_REQUEST['trendrange']) or !is_numeric($_REQUEST['trendrange']) )
  $_REQUEST['trendrange'] = 6;
if ( !isset($_REQUEST['trendhistory']) or !is_numeric($_REQUEST['trendhistory']) )
  $_REQUEST['trendhistory'] = 6;

$drop_args = array("trendrange", "trendhistory");

foreach ( $_REQUEST as $key => $value ) {
  if ( ! in_array($key, $drop_args) )
    $graph_args[] = rawurlencode($key) . "=" . rawurlencode( str_replace("_/graph_php?", "", $value) );
}

$query_string = preg_replace("/(&trendrange=)(\d+)/", "", $_SERVER['QUERY_STRING'] );
$query_string = preg_replace("/(&trendhistory=)(\d+)/", "", htmlspecialchars($query_string, ENT_QUOTES) );


?>
<center>
<div id="trend_range_menu">
<form id="trend_range_form">
Use data from last 
<?php
foreach ( $months_back as $index => $month ) {
  if (  $_REQUEST['trendhistory'] == $month )
    $checked = 'checked="checked"';
  else
    $checked = "";
?>
   <input OnChange='drawTrendGraph("<?php print $query_string ?>" + "&" + $("#trend_range_form").serialize()); return false;' type="radio" id="trendhistory-<?php print $month; ?>" name="trendhistory" value="<?php print $month; ?>" <?php print $checked; ?>/>
   <label for="trendhistory-<?php print $month; ?>"><?php print $month; ?></label>
<?php
}
?>
months&nbsp;|&nbsp;Extend trend line 
<?php

if ( !isset($_REQUEST['trendrange']) )
  $_REQUEST['trendrange'] = 6;

foreach ( $months_ahead as $index => $month ) {

  if (  $_REQUEST['trendrange'] == $month )
    $checked = 'checked="checked"';
  else
    $checked = "";

?>
   <input OnChange='drawTrendGraph("<?php print $query_string ?>" + "&" + $("#trend_range_form").serialize()); return false;' type="radio" id="range-<?php print $month; ?>" name="trendrange" value="<?php print $month; ?>" <?php print $checked; ?>/>
   <label for="range-<?php print $month; ?>"><?php print $month; ?></label>
<?php
}
?>
 months ahead</form></div>
</center>
<script type="text/javascript">
  $(function () {
    $("#trend_range_menu").buttonset();
  });
</script>