<select name="months" id="months" >
<option value="0" >Select Months *</option>
<option value="3000" >6 Months</option>
<option value="6000" >12 Months</option>
<option value="9000" >18 Months</option>
</select>
$message .= "<br>Selected Months : " . $_POST['months'];
Need to $post text, not value of a dropdown selected element.