Automated teller machine program

Hi all,
i m trying to make a program (client/server) of a Automated teller
machine talking with its bank server. i did it using 3 files, a clent,
a server and an application.
the program contains 2 bugs that i woud like you to help me solve them
1- the program take random choice for working or not which is too
weird to me (i m a beginer)
the program may work for one time properly, then not then yes,
eventhough i compile everytime.

2- whenever i enter a right value, i go to the right step if i enter
the password before the username it will not prompt me about a user
name instead, in case the pass i give is right i go to the next step
which is main menu what i want is to go step by step the procedure,
like if anything except the UserName was given even a right pass. the
program shall not take it, it should remain in the UserName step
untill entered correctly

for this i suppose the problem is in the if statements but i m not
sure how to fix them so i will show you what are the 'if' i m using on
both sides and if you can please help :

Fom the client side:
        modifiedsentence = inFromServer.readLine();

        String onoma = "MyBank";
        String onoma1 = "MyName";
        String Pass = "MyPass";
        // Print the server's reply
        System.out.println(">> Bank Server: " + modifiedsentence);

        //--------------------------------------------------------
        if (modifiedsentence.equalsIgnoreCase(onoma))
        {
            System.out.println("Enter your User Name");
        }
        if (modifiedsentence.equalsIgnoreCase(onoma1))
        {
            System.out.println("Enter your Password");
        }
        if (modifiedsentence.equalsIgnoreCase(Pass))
        {
            System.out.println(" ");
            System.out.println("MAIN MENU");
            System.out.println("---------");
            System.out.println("* w for Withdrawal");
            System.out.println("* d for Deposit");
            System.out.println("* c for check Balance");
}
------------------------------------------------------------------------------------------------------------------
From the server side:
        clientsentence = inFromClient.readLine();
        //Ask for a cardNumber
        Accepted = clientsentence.toUpperCase() +"\n";
        NotAccepted = clientsentence.toUpperCase() +" is NOT accepted "+
"\n";
        String Nom = "MyBank";
        String PreNom = "MyName";
        String PassWord = "MyPass";

        if (clientsentence.equalsIgnoreCase(Nom))
        {
            outToClient.writeBytes(Accepted);
        }
        if (clientsentence.equalsIgnoreCase(PreNom))
        {
            outToClient.writeBytes(Accepted);
        }
        if (clientsentence.equalsIgnoreCase(PassWord))
        {
            outToClient.writeBytes(Accepted);
        }
        else
        {
        outToClient.writeBytes(NotAccepted);
        }
==========================================================
i m pretty sure the problem is here so i must nest them in some way or
something else should be done, would you please help

Thank you all