javascript中CheckBox全选终极方案

<asp:Repeater ID="rptGroup" runat="server">
<HeaderTemplate>
<table width="100%" cellspacing="1" >
<tr>
<td width="3%" align="center" >
<input type="checkbox" id="chkAll" name="chkAll" value="checkbox"
onclick="checkAll ('chkAll',this);" />
</td>
</tr>
</HeaderTemplate>
<ItemTemplate>
<tr>
<td align="center" >
<input type="checkbox" name="chkSelect" value='<%# Eval("ID") %>'
onclick="checkAll('chkAll',this);"/>
</td>
</tr>
</ItemTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
</asp:Repeater>

function checkAll(chkAllID, thisObj) {
var chkAll = document.getElementById(chkAllID);
var chks = document.getElementsByTagName("input");
var chkNo = 0;
var selectNo = 0;
for (var i = 0; i < chks.length; i++) {
if (chks[i].type == "checkbox") {
//全选触发事件
if (chkAll == thisObj) {
chks[i].checked = thisObj.checked;
}
//非全选触发
else {
if (chks[i].checked && chks[i].id != chkAllID)
selectNo++;
}
if (chks[i].id != chkAllID) {
chkNo++;
}
}
}
if (chkAll != thisObj) {
chkAll.checked = chkNo == selectNo;
}
}

function checkSelectNo(chkAllID) {
var chks = document.getElementsByTagName("input");
var selectNo = 0;
for (var i = 0; i < chks.length; i++) {
if (chks[i].type == "checkbox") {
if (chks[i].id != chkAllID && chks[i].checked) {
selectNo++;
}
}
}
return selectNo;
}