js的问题，单选框默认选中

                <%
                    for (int j = 0; userList != null && j < userList.size(); j++) {
                        DynaBean user = (DynaBean) userList.get(j);
                        String userId = StringUtil.getStr(user.get("pk"));
                        String userName = StringUtil.getStr(user.get("cname"));
                %>
                <TR class="tr_form">
                    <TD height="24" class="txt">  
                      <INPUT type="radio" name="userId"   checked id="userId<%=j %>" value="<%=userId %>">
                      
                      <%=userName %></TD>
                </TR>
                <%
                        }
                %>

 

怎么让第一个默认选中

答案：你这样每个都选中了，只需改为这样：
if(j==0)
{
<INPUT type="radio" name="userId"   checked id="userId<%=j %>" value="<%=userId %>">
}
else
{
<INPUT type="radio" name="userId"   id="userId<%=j %>" value="<%=userId %>">
}
 类里面加一个字段，值是checked，放到radio中，设置你想到要