Java Database Connectivity (JDBC)

I am using JBuilder5 which comes with jdk1.3. I have installed oracle 8.1.7 Enterprise version.
I am using Win NT 4.0.
I have set the PATH variable as E:\oracle\ora81\lib; and
CLASSPATH as : E:\oracle\ora81\jdbc\lib\classes12.zip;E:\oracle\ora81\jdbc\lib\nls_charset12.zip;
My JDBC code is

package sample2;
import java.sql.*;

public class Two {
Connection con;
Statement st;

public Two() {
try{
Class.forName("oracle.jdbc.driver.OracleDriver");
con = DriverManager.getConnection("jdbc:oracle:oci8:@First","scott","tiger");
st = con.createStatement();
ResultSet rs = st.executeQuery("Select * from Book");
while(rs.next())
{
System.out.print(rs.getInt("ID")+"\t");
System.out.print(rs.getString("title")+"\t");
System.out.print(rs.getString("author")+"\t");
System.out.print(rs.getString("subject")+"\t");
System.out.println(rs.getInt("copies")+"\t");
}
st.close();
con.close();
}
catch(Exception ex)
{
System.out.println("Exception : " + ex.toString());
}
}
public static void main(String[] args) {
Two two1 = new Two();
}
}

I am getting this exception:
Exception : java.lang.ClassNotFoundException: oracle.jdbc.driver.OracleDriver

I can understand that the classpath for the driver is the problem here. I tried addding classes111.zip and nls_charset11.zip also in the class path. Even then I get the same exception.
Can anybody help me fix this problem?

Thanks in advance.