全选

function CheckSelBox(box)   
{
    for (var i=0;i<document.forms[0].elements.length;i++)
    {
        var e = document.forms[0].elements[i];
        if (e.type=='checkbox')
        {
            var o=e.name.lastIndexOf('chbItem');
            if(o!=-1)
            {
                e.checked = box.checked;
             }
        }
    }
}