Thanks pbl...

Still getting the error. I have tried this.

package javaapplication2;

import java.sql.*;
public class JavaApplication2
{
    public static void main(String args[])
    {
        int i=0;
        try
        {
            String str="Select fname from students";
            Class.forName("net.sourceforge.jtds.jdbc.Driver");
            Connection con=DriverManager.getConnection("jdbc:jtds:sqlserver://monika-pc/mm");
            System.out.println("Connection open");
            Statement stmt=con.createStatement();
            ResultSet rs=stmt.executeQuery(str);
            System.out.println("fname\t");
            while(i<3)
            {
                rs.next();
                String lname=rs.getString("lname");
                System.out.println(lname);
                i++;
                
            }
                con.close();    
        }
        catch(Exception ex)
        {
            ex.printStackTrace();
        }
    }
}

but I am getting the following error :

run:
java.lang.ClassNotFoundException: net.sourceforge.jtds.jdbc.Driver
	at java.net.URLClassLoader$1.run(URLClassLoader.java:200)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
	at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:276)
	at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
	at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
	at java.lang.Class.forName0(Native Method)
	at java.lang.Class.forName(Class.java:169)
	at javaapplication2.JavaApplication2.main(JavaApplication2.java:12)
BUILD SUCCESSFUL (total time: 1 second)

pbl, on 19 August 2012 - 07:41 PM, said:

Its all right. I know my question is not much of intelligence but and I have never faced this problem in my 1.5 years of Java experience. Although I have posted my question about 3 days ago, still I don't got the answer . So,what's the benefit of getting reputations here.

but by right clicking on MY COMPUTER , the name is " monika-pc"

by writting " C:/>hostname" in cmd ,I am getting an error :
" 'hostname' is not recognized as an internal or external command,operable program or batch file. "