全选checkbox

XHtml

<label><input type="checkbox" name="abc" onclick="checkall(this.form)" value="checkbox" />全选</label>

JavaScript

<script language="javascript">
function checkall(form) {
    var c = 'abc';
    for(var e = 0; e < form.elements.length; e++) {
        var v = form.elements[e];
        v.checked = form.elements[c].checked;
    }
}
</script>