Try Catch printing problmes JavaME

[OMGNinja]

Ok so I have the gas mileage calculator working relly nice in fact all the error handeling is working and i get the values form the text boxes but when I am trying to print out the results from the input it displays nothing prints out whats wrong with this?
here is the try catch block;

try{
     if (command == OKCmd){
      gInput = Integer.parseInt(gas.getString());
      bMInput = Integer.parseInt(bm.getString());
      eMInput = Integer.parseInt(em.getString());
    boolean  ok = true;
      //error checking
      //see if gas or ending mileage is 0
      if(gInput == 0)
      {
        ok = false;
        form.append("Gallons is 0");
        
      }
      if(eMInput == 0)
      {
          ok = false;
          form.append("End Millage is 0");
      }


      //see if begning miles are larger than ending miles

      if(bMInput >= eMInput)
      {
          ok = false;
          form.append("End mileage less than begin mileage 12");
      }


      //see if any value is negative
      if(gInput < 0)
      {
          ok = false;
          form.append("Gallons is negative");
      }
      if(bMInput < 0)
      {
          ok = false;
          form.append("Begning Miles is negative");
      }

       if(eMInput < 0)
      {
           ok = false;
           form.append("Ending Miles is negative");
      }


         //gas mileage = (em - bm)/ gas;
       if(ok = true){
       
        form.append("The Amount of Gas used is " + (eMInput - bMInput) / gInput);
       }
    

     }
}catch(Exception ex){
      }

here is the whole thing if that helps;

import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import javax.microedition.lcdui.TextField;



public class Gas extends MIDlet  implements CommandListener {

  
    //gas mileage = (em - bm)/ gas;

TextField gas; //gas in gallons
TextField bm;  //begingin mileage
TextField em;  //ending mileage
private int gInput;
private int bMInput;
private int eMInput;



    private Form form;
    private Command quit;
    private Command OKCmd;


public Gas(){
    gas = new TextField("Gas in Gallons:", "", 10, TextField.ANY);
    bm = new TextField("Begining Mileage :", "", 10, TextField.ANY);
    em = new TextField("Ending Mileage :", "", 10, TextField.ANY);
    

      form = new Form("Gas Milages");
     
      form.setCommandListener(this);
      quit = new Command("Quit", Command.SCREEN, 1);
      form.addCommand(quit);
      OKCmd = new Command("OK", Command.SCREEN, 1);
      form.addCommand(OKCmd);
      form.append(gas);
      form.append(bm);
      form.append(em);
      
      
      


   }
protected void startApp() throws MIDletStateChangeException{

      Display.getDisplay(this).setCurrent(form);
   }


   protected void pauseApp(){
   }


   protected void destroyApp(boolean unconditional)
           throws MIDletStateChangeException{
   }


   // Handle Events generated by Commands
   public void commandAction(Command command, Displayable displayable){
try{
     if (command == OKCmd){
      gInput = Integer.parseInt(gas.getString());
      bMInput = Integer.parseInt(bm.getString());
      eMInput = Integer.parseInt(em.getString());
    boolean  ok = true;
      //error checking
      //see if gas or ending mileage is 0
      if(gInput == 0)
      {
        ok = false;
        form.append("Gallons is 0");
        
      }
      if(eMInput == 0)
      {
          ok = false;
          form.append("End Millage is 0");
      }


      //see if begning miles are larger than ending miles

      if(bMInput >= eMInput)
      {
          ok = false;
          form.append("End mileage less than begin mileage 12");
      }


      //see if any value is negative
      if(gInput < 0)
      {
          ok = false;
          form.append("Gallons is negative");
      }
      if(bMInput < 0)
      {
          ok = false;
          form.append("Begning Miles is negative");
      }

       if(eMInput < 0)
      {
           ok = false;
           form.append("Ending Miles is negative");
      }


         //gas mileage = (em - bm)/ gas;
       if(ok = true){
       
        form.append("The Amount of Gas used is " + (eMInput - bMInput) / gInput);
       }
    

     }
}catch(Exception ex){
      }
       
       
       try
      {
         if (command == quit)
         {
            destroyApp(true);
            notifyDestroyed();
         }
      }

      catch (MIDletStateChangeException me){
      }
   }
}

[dlorde]

I don't see any code to print anything.

Optimism is an occupational hazard of programming: testing is the treatment...
K. Beck

[OMGNinja]

this is the part that prints out the result
if(ok = true){

form.append("The Amount of Gas used is " + (eMInput - bMInput) / gInput);

[dlorde]

OK. Ignoring, for now, the difference between 'printing out' and 'appending to a form'...

if(ok = true){

What does operator '=' do?

The cheapest, fastest, and most reliable components of a computer system are those that aren't there...
G. Bell

[OMGNinja]

see if the boolean ok is true or not. Did I use that = operator wrong or is it .equals?

[dlorde]

Surely you can make the effort to look it up?

To save you the effort, '=' is the assignment operator. The equals operator is '=='.

The irony is that you don't even need to use the equals operator, because the variable 'ok' is a boolean that you can test directly. Comparing it with 'true' is redundant.

Think twice, code once...
Anon.