JS操作Listbox

    function listbox_selectall(listID, isSelect) {
        var listbox = document.getElementById(listID);
        for(var count=0; count < listbox.options.length; count++) {
            listbox.options[count].selected = isSelect;
    }
}

function listbox_move(listID, direction) {
    var listbox = document.getElementById(listID);
    var selIndex = listbox.selectedIndex;

    if(-1 == selIndex) {
        alert("Please select an option to move.");
        return;
    }

    var increment = -1;
    if(direction == 'up')
        increment = -1;
    else
        increment = 1;

    if((selIndex + increment) < 0 ||
        (selIndex + increment) > (listbox.options.length-1)) {
        return;
    }

    var selValue = listbox.options[selIndex].value;
    var selText = listbox.options[selIndex].text;
    listbox.options[selIndex].value = listbox.options[selIndex + increment].value
    listbox.options[selIndex].text = listbox.options[selIndex + increment].text

    listbox.options[selIndex + increment].value = selValue;
    listbox.options[selIndex + increment].text = selText;

    listbox.selectedIndex = selIndex + increment;
}

function listbox_moveacross(sourceID, destID) {
    var src = document.getElementById(sourceID);
    var dest = document.getElementById(destID);

    for(var count=0; count < src.options.length; count++) {
        if(src.options[count].selected == true) {
                var option = src.options[count];

                var newOption = document.createElement("option");
                newOption.value = option.value;
                newOption.text = option.text;
                newOption.selected = true;
                try {
                         dest.add(newOption, null); //标准
                         src.remove(count, null);
                 }catch(error) {
                         dest.add(newOption); // 针对IE的情况
                         src.remove(count);
                 }
                count--;
        }
    }
}