Null Pointer Exception and Illegal Arguement when ran with Wireless Toolkit

Question

The following code throws a null pointer exception after it tried to initialize the textBox. I am not sure if there is something I am not importing, or if it's just because I'm sick and my head is cloudy. :-}.
I am using Wireless Toolkit 2.2 and Java 5.0
Anyhelp would be appreicated. Thank You.
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
public class TacticalTestMain extends MIDlet implements CommandListener {
     private Display display;
     private Form formMain;
     private TextBox tbHelp;          //Text Box for help Command
     private Command cmExit;          //A button to exit midLet
     private Command cmBack;          //Go "back" to main form
     private Command cmHelp;          //Ask for help
     public TacticalTestMain()
          display = Display.getDisplay(this);
          formMain = new Form("Tactical Survey Program");
          cmExit = new Command("Exit", Command.SCREEN, 1);
          cmBack = new Command("Back", Command.BACK, 1);
          cmHelp = new Command("Help", Command.HELP, 1);
          formMain.addCommand(cmExit);
          formMain.addCommand(cmBack);
          formMain.addCommand(cmHelp);
          formMain.setCommandListener(this);
          System.out.println("Before Create Text Box");
          //Create the help textBox with a max of 25 charecters
          tbHelp = new TextBox("HeLp", "You can press the back button", 25, 0);
          tbHelp.addCommand(cmBack);
          tbHelp.setCommandListener(this);
          System.out.println("AfTER Create Text Box");               
     }//end constructor
     public void startApp()
          System.out.println("Inside StartApp()");
          display.setCurrent(formMain);
     }//end startApp()
     public void pauseApp()
     }//end pauseApp
     public void destroyApp(boolean unconditional)
          notifyDestroyed();
     }//end destroyApp()
     //Check to see if the exit button was selected
     public void commandAction(Command c, Displayable d)
          System.out.println("Inside commandAction()");
          String sLabel = c.getLabel();
          if(sLabel.equals("Exit"))
               destroyApp(true);
Errors from the KToolbar:
Running with storage root DefaultColorPhone
Before Create Text Box
Unable to create MIDlet TacticalTestMain
java.lang.IllegalArgumentException
     at javax.microedition.lcdui.TextField.setChars(+105)
     at javax.microedition.lcdui.TextField.setString(+27)
     at javax.microedition.lcdui.TextField.<init>(+134)
     at javax.microedition.lcdui.TextBox.<init>(+74)
     at TacticalTestMain.<init>(+134)
     at java.lang.Class.runCustomCode(+0)
     at com.sun.midp.midlet.MIDletState.createMIDlet(+19)
     at com.sun.midp.midlet.Selector.run(+22)
Execution completed.
743701 bytecodes executed
23 thread switches
741 classes in the system (including system classes)
4071 dynamic objects allocated (120440 bytes)
2 garbage collections (91412 bytes collected)

Answer 1

Hi zoya,
Here is the problem:
tbHelp = new TextBox("HeLp", "You can press the back button", 25, 0);
This line declares a maximum textbox size of 25 but in reality he is declaring a textbox of size 29.
Thats why it is throwing the illegal argument.
happy coding :)