There are two ways you can look at doing, the second way is a faster way for php, time difference in it wouldn't be much though.
<select id='subject' name="title">
<option value='0'>Email Subject</option>
<option value='1'>Affiliation</option>
<option value='2'>Bug Report</option>
<option value='3'>Chit-Chat</option>
<option value='4'>Web Development</option>
<option value='5'>Other</option>
</select>
<?php
switch( $_POST['title'] ) {
case '0':
$header = 'Email Subject';
break;
case '1':
$header = 'Affiliation';
break;
case '2':
$header = 'Bug Report';
break;
case '3':
$header = 'Chit-Chat';
break;
case '4':
$header = 'Web Development';
break;
case '5':
$header = 'Other';
break;
}
?>
OR
<select id='subject' name="title">
<option value='Email Subject'>Email Subject</option>
<option value='Affiliation'>Affiliation</option>
<option value='Bug Report'>Bug Report</option>
<option value='Chit-Chat'>Chit-Chat</option>
<option value='Web Development'>Web Development</option>
<option value='Other'>Other</option>
</select>
<?php
$header = $_POST['title'];
#OR you can just use
$_POST['title'];
?>
Matt