<table>
    <tbody>
        <tr>
            <td>
                <input class="txtInput" type="text" name="test1" value="test1val" readonly/>
            </td>
            <td>
                <input type="button" class="btnEdit" name="editName" value="Edit"/>
            </td>
        </tr>
        <tr>
            <td>
                <input class="txtInput" type="text" name="test2" value="test2val" readonly />
            </td>
            <td>
                <input type="button" class="btnEdit" name="editName" value="Edit" />
            </td>
        </tr>
    </tbody>
</table>

$(document).ready(function () {
    $('.btnEdit').click(function () {
        if ($('.txtInput').prop('readonly')) {
            $('.txtInput').removeAttr('readonly');
        }
        else {
            $('.txtInput').attr('readonly', 'readonly')
        }
    });
});