servelt problem

[serifu]

i have a servlet which select items from a database:
here is the code..
public class TreeServlet extends HttpServlet {
public void doGet(HttpServletRequest req, HttpServletResponse res)
throws ServletException, IOException {
res.setContentType("text/html");
PrintWriter out = res.getWriter();
.............
ResultSet rs;
..............
Class.forName("sun.jdbc.odbc.JdbcOdbcDriver");
con = DriverManager.getConnection("jdbc:odbc:merant","wwwedfro","php404");
.............
while ( rs.next() )
out.print(rs.getString("fieldname"));
//output exactly on yhe screen what is in that field
//but if i try to assign that value to othe variable name var i mean:
var = new String( rs.getString("fieldname") ) or var = rs.getString("fieldname")
on screen apears error 500:internal server Error
....
javax.servlet.ServletException: Servlet Could not display records.
at TreeServlet.doGet(TreeServlet.java, Compiled Code)
at javax.servlet.http.HttpServlet.service(HttpServlet.java, Compiled Code)
at javax.servlet.http.HttpServlet.service(HttpServlet.java, Compiled Code)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java, Compiled Code)
at org.apache.tomcat.core.Handler.service(Handler.java, Compiled Code)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java, Compiled Code)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java, Compiled Code)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java, Compiled Code)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java, Compiled Code)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java, Compiled Code)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java, Compiled Code)
at java.lang.Thread.run(Thread.java:479)

Root cause:
java.sql.SQLException: No data found
at sun.jdbc.odbc.JdbcOdbc.standardError(JdbcOdbc.java, Compiled Code)
at sun.jdbc.odbc.JdbcOdbc.SQLGetDataString(JdbcOdbc.java, Compiled Code)
at sun.jdbc.odbc.JdbcOdbcResultSet.getDataString(JdbcOdbcResultSet.java, Compiled Code)
at sun.jdbc.odbc.JdbcOdbcResultSet.getString(JdbcOdbcResultSet.java, Compiled Code)
at sun.jdbc.odbc.JdbcOdbcResultSet.getString(JdbcOdbcResultSet.java, Compiled Code)
at TreeServlet.doGet(TreeServlet.java, Compiled Code)
at javax.servlet.http.HttpServlet.service(HttpServlet.java, Compiled Code)
at javax.servlet.http.HttpServlet.service(HttpServlet.java, Compiled Code)
at org.apache.tomcat.core.ServletWrapper.doService(ServletWrapper.java, Compiled Code)
at org.apache.tomcat.core.Handler.service(Handler.java, Compiled Code)
at org.apache.tomcat.core.ServletWrapper.service(ServletWrapper.java, Compiled Code)
at org.apache.tomcat.core.ContextManager.internalService(ContextManager.java, Compiled Code)
at org.apache.tomcat.core.ContextManager.service(ContextManager.java, Compiled Code)
at org.apache.tomcat.service.http.HttpConnectionHandler.processConnection(HttpConnectionHandler.java, Compiled Code)
at org.apache.tomcat.service.TcpWorkerThread.runIt(PoolTcpEndpoint.java, Compiled Code)
at org.apache.tomcat.util.ThreadPool$ControlRunnable.run(ThreadPool.java, Compiled Code)
at java.lang.Thread.run(Thread.java:479)

I'm on win200 and tomcat 3.2.3 server...
}