jsp 自定义标签实现下拉菜单，如何获取下拉菜单的内容?

[江东橘子]

描述：用ＪＳＰ　ＴＡＧ实现了从数据库中获取内容，然后显示在下拉菜单中。
问题：现在当我选中下拉菜单总的一个选项时，如何在ＪＳＰ页面获取她的内容？

其他信息：ListDownSelect.tld中定义了table（获取数据库表名）,value(数据库的主键),label(名字)


======ListDownSelect.tld==========
<tag>
<variable>
<name-given>university_name</name-given>
<variable-class>Integer</variable-class>
<declare>true</declare>
<scope>AT_END</scope>
</variable>

<name>select</name>
<tag-class>pro.shoping.Tag.HtmlTag</tag-class>
<body-content>empty</body-content>

<!-- 属性 -->
<attribute>
<name>table</name>
<required>true</required>
</attribute>


<attribute>
<name>value</name>
<required>true</required>
</attribute>

<attribute>
<name>label</name>
<required>true</required>
</attribute>

</tag>

=======HtmlTag.java=========
public void doTag() throws JspException, IOException {
// TODO Auto-generated method stub
String sql = "select * from "+table;

ResultSet rs = jUtil.executeQuery(sql);
JspWriter out = getJspContext().getOut();
JspContext jspCtx=getJspContext();
out.print("<select name="+table+"">");
out.print("<option value=-1>--请选择--</option>");
try {
while (rs != null && rs.next()) {
String v = rs.getString(value);
String l = rs.getString(label);
out.print("<option value=" + v + ">" + l + "</option>");
}
} catch (SQLException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
out.print("</select>");
// jspCtx.setAttribute("university_name",new Integer("kind"));
super.doTag();
}