preparedstatement

请高手指教一下，我初学，不知道究竟怎么回事，为什么会没有定义呢？
代码如下：

<%
String ID = request.getParameter("ID");
String password = request.getParameter("password");
String rpassword = request.getParameter("rpassword");
String name = request.getParameter("name");
String sex = request.getParameter("sex");
String year = request.getParameter("year");
if(year.length() ==1) year = "0"+year;
String mouth = request.getParameter("mouth");
if(mouth.length() == 1) mouth = "0"+mouth;
String day = request.getParameter("day");
if(day.length() == 1) day = "0"+day;
String date = year+"-"+mouth+"-"+day;
String description = request.getParameter("description");

Connection con = null;
PreparedStatement psm = null;
ResultSet rs = null;
try
{
Class.forName