这段jsp代码用ajax怎么实现

<table border="1">
<tr align="center" valign="middle">
<%
int bj = 3;
GNewMsgs gs = new GNewMsgs();
int maxLevels = gs.getLevels(bj);
ArrayList list = new ArrayList();
ArrayList zList = new ArrayList();
for (int i = 0; i <= maxLevels; i++) {
System.out.println("i:" + i);
list = gs.getCs(bj, i);
zList = gs.getYgs(bj, i);

for (int z = 0; z < zList.size(); z++) {
TailBean bean = (TailBean) zList.get(z);
int count = Integer.parseInt(bean.getCHILDCOUNT()
.toString()) + 1;
//System.out.println("bean - " + count);
%>
<td rowspan=<%=count %>>
<div align="center"><%=bean.getCNAME()%></div>
</td>

---

动态获得列的跨度?