Marcar todos

Marcar todos los checkbox desde un solo control

HTML

<table style="border: 1px solid black; padding: 5px;">
    <thead>
        <tr>
            <th style="width: 15px;">
                <input id="selectall0" type="checkbox">
            </th>
            <th>Marcar todos</th>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>
                <input value="1" id="selectall0" type="checkbox">
            </td>
            <td>Item 1</td>
        </tr>
        <tr>
            <td>
                <input value="2" class="selectall0" type="checkbox">
            </td>
            <td>Item 2</td>
        </tr>
        <tr>
            <td>
                <input value="3" class="selectall0" type="checkbox">
            </td>
            <td>Item 3</td>
        </tr>
        <tr>
            <td>
                <input value="4" class="selectall0" type="checkbox">
            </td>
            <td>Item 4</td>
        </tr>
        <tr>
            <th style="width: 15px;">
                <input id="selectall1" type="checkbox">
            </th>
            <th>Marcar todos</th>
        </tr>
        <tr>
            <td>
                <input value="1" class="selectall1" type="checkbox">
            </td>
            <td>Item 1</td>
        </tr>
        <tr>
            <td>
                <input value="2" class="selectall1" type="checkbox">
            </td>
            <td>Item 2</td>
        </tr>
        <tr>
            <td>
                <input value="3" class="selectall1" type="checkbox">
            </td>
            <td>Item 3</td>
        </tr>
        <tr>
            <td>
                <input value="4" class="selectall1" type="checkbox">
            </td>
            <td>Item 4</td>
        </tr>
    </tbody>
</table>

JavaScript

$("input[id^='selectall']").on('click', function () {
    //verificar el estado de ese checkbox si esta marcado o no
    var checked_status = this.checked;

    /*
     * asignarle ese estatus a cada uno de los checkbox
     * que tengan la clase "selectall"
     */
    $("^.selectall"+id).each(function () {
        this.checked = checked_status;
    });
});