I used this php function to generate the options, and insert it into my HTML
<?php
# code to output a set of options for a numeric drop down list
# parameters: (start, end, step, format, default)
function numericoptions($start, $end, $step, $formatstring, $default)
{
$retstring = "";
for($i = $start; $i <= $end; $i = $i + $step)
{
$retstring = $retstring . '<OPTION ';
$retstring = $retstring . 'value="' . sprintf($formatstring,$i) . '"';
if($default == $i)
{
$retstring = $retstring . ' selected="selected"';
}
$retstring = $retstring . '>' . sprintf($formatstring,$i) . '</OPTION> ';
}
return $retstring;
}
?>
And then in my webpage code I use it as below;
<select id="endmin" name="endmin">
<?php echo numericoptions(0,55,5,'%02d',$endmin); ?>
</select>
If $endmin is created from a _POST variable every time the page is loaded (and this code is inside a form which posts) then the previously selected value is selected by default.