$gear_box = "Manual";
$mech->select("cargear", "$gear_box"); 

##</code><code>##

<select name="cargear" id="cargear" class="form_widt h">
<option value='0' >All</option>
<option value='2' >Automatic</option>
<option value='4' >No gear</option>
<option value='1' >Manual</option>