Problem in Connection Pooling

[Kumar Abhay-CAK203C]

Hello,

I am trying to set up connection pooling with Tomcat 4.1.29 and Oracle 9i
I am getting the below error:

org.apache.commons.dbcp.SQLNestedException: Cannot create JDBC driver of class '' for 
connect URL 'null', cause:java.sql.SQLException: No suitable driver

Please tell me what to do to resolve this. I am able to lookup dB. But on trying to 
fetch data from dB I am getting this error.

Please Help

Regards
Abhay

Details:

Server.xml
    <Resource name="estimation" scope="Shareable" type="javax.sql.DataSource"/>
    <ResourceParams name="estimation">
      <parameter>
        <name>validationQuery</name>
        <value>select sysdate from dual</value>
      </parameter>
      <parameter>
        <name>maxWait</name>
        <value>5000</value>
      </parameter>
      <parameter>
        <name>maxActive</name>
        <value>4</value>
      </parameter>
      <parameter>
        <name>password</name>
        <value>pass</value>
      </parameter>
      <parameter>
        <name>url</name>
        <value>jdbc:oracle:thin:@server_name:1521:DEV</value>
      </parameter>
      <parameter>
        <name>driverClassName</name>
        <value>oracle.jdbc.driver.OracleDriver</value>
      </parameter>
      <parameter>
        <name>maxIdle</name>
        <value>2</value>
      </parameter>
      <parameter>
        <name>username</name>
        <value>eppsys</value>
      </parameter>
    </ResourceParams>


        <Context className="org.apache.catalina.core.StandardContext" 
cachingAllowed="true" charsetMapperClass="org.apache.catalina.util.CharsetMapper" 
cookies="true" crossContext="false" debug="0" displayName="Estimation" 
docBase="C:\Estimation" mapperClass="org.apache.catalina.core.StandardContextMapper" 
path="/Estimation" privileged="false" reloadable="false" swallowOutput="false" 
useNaming="true" wrapperClass="org.apache.catalina.core.StandardWrapper">

          <Logger className="org.apache.catalina.logger.FileLogger" debug="0" 
directory="logs" prefix="localhost_estimation_log." suffix=".txt" timestamp="true" 
verbosity="1"/>

        </Context>

Web.xml

<resource-ref>
        <res-ref-name>jdbc/estimation</res-ref-name>
        <res-type>javax.sql.DataSource</res-type>
        <res-auth>Shareable</res-auth>
</resource-ref>

Class Path

.;C:\Estimation;C:\Tomcat\common\lib\servlet.jar;C:\Tomcat\common\lib\mail.jar;C:\Tomcat\common\lib\activation.jar;C:\Tomcat\common\lib\jndi.jar;C:\Tomcat\common\lib\jdbc2_0-stdext.jar;C:\Tomcat\common\lib\classes12.jar

Tried with oracle.jar and ojdbc14.jar