JSP中打印数据库表的问题

原码
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.sql.*" %>
<HTML>
<BODY>
 <%
    Connection con;
    Statement sql; 
    ResultSet rs;
    try{
        Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
       }
    catch(ClassNotFoundException e){}
    try { 
         con=DriverManager.getConnection("jdbc:odbc:sun","sa","");
         sql=con.createStatement();
         rs=sql.executeQuery("SELECT * FROM students");
         out.print("<Table Border>");
         out.print("<TR>");
            out.print("<TH width=100>"+"学号");
            out.print("<TH width=100>"+"姓名");
            out.print("<TH width=50>"+"数学成绩");
            out.print("<TH width=50>"+"英语成绩");
            out.print("<TH width=50>"+"物理成绩");
         out.print("</TR>");
       while(rs.next())
       {
        out.print("<TR>");
             out.print("<TD >"+rs.getString(1)+"</TD>"); 
             out.print("<TD >"+rs.getString(2)+"</TD>");
             out.print("<TD >"+rs.getInt("数学成绩")+"</TD>"); 
             out.print("<TD >"+rs.getInt("英语成绩")+"</TD>");
             out.print("<TD >"+rs.getInt("物理成绩")+"</TD>");   
         out.print("</TR>") ; 
        }
        out.print("</Table>");
        con.close();
     }
   catch(SQLException e1) {}
 %>
</BODY>
</HTML>数据库和表都已经建好了,可是在用浏览器运行的时候页面上什么也没有