Problem using Input stream reader - unable to read values in variables

Question

Hi,
I have a program that need to input an access code. If the code is correct a message appears "Valid access code". Till this part, the codes works fine.
The problem is here:
If not correct a prompt is displayed asking the user whether he want to input another code. Whether Y/N, the program always ask for the input. Can anyone tell me what's the problem in the code??
import     java.io.*;
public     class     testwhile
     public static void main(String args[])
          //initialisation for input
          InputStreamReader stdin =
                    new InputStreamReader(System.in);
          BufferedReader console =
                    new BufferedReader(stdin);
          //array to store copier access codes and associated max number of copies
          int[][] arr_copier = new int[3][2];
          int     i = 0;
          String c_code;
          int p_validrow; //use to input copier access code
          String     p_reply,p_tryagain, p_found;
          int copier_code;
          //assigning values to array
          arr_copier[0][0] = 450101;
          arr_copier[1][0] = 450202;
          arr_copier[2][0] = 430303;
          arr_copier[0][1] = 500;
          arr_copier[1][1] = 2000;
          arr_copier[2][1] = 100;
          p_tryagain ="N";
          p_found = "N";
          p_validrow = 0;
          c_code = "0";
          try
          do
                    System.out.print("Input code: ");
                    c_code = console.readLine();
                    copier_code = Integer.parseInt(c_code);
                    for (int r=0;r<=2;r++)
                         // System.out.println(r + " = " + arr_copier[r][0]);
                         if (copier_code == arr_copier[r][0])
                              System.out.println("Value found");
                              p_found = "Y";
                              p_validrow = r;
                              break; // to know row number so as to pick the number of copies for the selected access code
                         else
                              System.out.println("NOT found");
                              p_found = "N";
                    if (p_found == "N")
                         System.out.println("Invalid access code");
                         System.out.print("Do you want to try another code?");
                         p_tryagain = console.readLine();
                    else     
                         System.out.println("VALID access code");
                         p_tryagain = "N";
               p_tryagain = p_tryagain;
               System.out.println("try again" + p_tryagain);
          while (p_tryagain != "N");
          catch(IOException ioex)
                    System.out.println("Error Exception" + ioex);
}

Answer 1

Never compare Strings using Object equality or inequality ("==" resp. "!=").
Use [url http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html#equals(java.lang.Object)]String#equals (or [url http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html#indexOf(java.lang.String)]String#indexOf or [url http://java.sun.com/j2se/1.5.0/docs/api/java/lang/String.html#matches(java.lang.String)]String#matches).
Please use code tags when posting code. This means wrapping your text between [code[/b]][[/b]code] tags. See the [url http://forum.java.sun.com/help.jspa?sec=formatting]Formatting tips.