Exception is not clear

HTTP Status 500 -

type Exception report

message

description The server encountered an internal error () that prevented it from fulfilling this request.

exception

javax.servlet.ServletException: Servlet Could not display records.
DisplayServlet.doPost(DisplayServlet.java:72)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

root cause

java.sql.SQLException: [Microsoft][ODBC Driver Manager] Data source name not found and no default driver specified
sun.jdbc.odbc.JdbcOdbc.createSQLException(Unknown Source)
sun.jdbc.odbc.JdbcOdbc.standardError(Unknown Source)
sun.jdbc.odbc.JdbcOdbc.SQLDriverConnect(Unknown Source)
sun.jdbc.odbc.JdbcOdbcConnection.initialize(Unknown Source)
sun.jdbc.odbc.JdbcOdbcDriver.connect(Unknown Source)
java.sql.DriverManager.getConnection(Unknown Source)
java.sql.DriverManager.getConnection(Unknown Source)
DisplayServlet.doPost(DisplayServlet.java:54)
javax.servlet.http.HttpServlet.service(HttpServlet.java:641)
javax.servlet.http.HttpServlet.service(HttpServlet.java:722)

note The full stack trace of the root cause is available in the Apache Tomcat/7.0.11 logs.
Apache Tomcat/7.0.11


I tried to connect to database using a java application & did it quite easily but
in case of servlet the above exception is only displayed .
can anyone tell me where i am going wrong..
Thanks.

can you post code of this DisplayServlet

Are you using data-source defined at tomcat server . are you sure that you are using the right JNDI name.