Why the input and the select do not get the same width?

Question

I have a table with two rows. The first row contains an input and the second row contains a select. Even though I have set their widths to be 100%, the select box is a few pixels smaller than the input. Any ideas why is this so and how can I set their widths to be equal to each other and as big as possible (e.g. %100) in a way that works across all (A-grade) browsers?

<table width="100%" style="margin-top: 5px;">
<tr>
    <td width="35"><label for="desc">Description</label></td>
    <td>
        <input type="text" style="width: 100%;" name="desc" id="desc" />
    </td>
</tr>
<tr>
    <td width="35"><label for="group">Group</label></td>
    <td>
        <select id="group" name="group" style="width: 100%; line-height: 17px;">            
            <option value="val">name</option>            
        </select>
    </td>
</tr>
</table>

Answer 1

This just seems to be the problem with browsers rendering form elements differently. Try fully defining their styles, like border width etc.