Can anyone help me?

Im looking to write the information selected in the Java mobile application to a text file and im not sure where to start, here is the code i have so far:

package hello;
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;

public class Rater extends MIDlet implements CommandListener
{
private Display mDisplay;
private Alert mAlert;
private Form mForm;
private ChoiceGroup chcFoodsold, chcEstablishmentType;
private TextField ID, txtPlaceName, txtLocation;
private String strPlace, strLocation, strID;

public Rater()
{
String [] EstablishmentType = {"Bar", "Restaruant", "Cafe'"};
String [] Foodsold = {"Tapas", "Pizza", "Pasta", "English Breakfast", "Roast Dinner", "Pie and Mash"};
mForm = new Form("Enter your order details");
ID = new TextField("ID*: ", null, 4, TextField.NUMERIC);
chcEstablishmentType = new ChoiceGroup("Type of Establishment*", Choice.EXCLUSIVE, EstablishmentType, null);
chcFoodsold = new ChoiceGroup("Food Sold*", Choice.EXCLUSIVE, Foodsold, null);
txtPlaceName = new TextField("Establishment Name*:", null, 15, TextField.ANY);
txtLocation = new TextField("Location*:", null, 15, TextField.ANY);
mForm.append(ID);
mForm.append(txtPlaceName);
mForm.append(txtLocation);
mForm.append(chcEstablishmentType);
mForm.append(chcFoodsold);
mForm.addCommand(new Command("Exit", Command.EXIT, 0));
mForm.addCommand(new Command("Next", Command.SCREEN, 0));
mForm.setCommandListener(this);
mAlert = new Alert("Your order", "", null, AlertType.CONFIRMATION);
mAlert.addCommand(new Command("Back", Command.BACK, 0));
mAlert.addCommand(new Command("Confirm", Command.OK,1));
mAlert.setTimeout(Alert.FOREVER);
}

protected void startApp()
{
mDisplay = Display.getDisplay(this);
mDisplay.setCurrent(mForm);
}


public void commandAction(Command c, Displayable d)
{
if (c.getLabel().equals("Exit"))
{
notifyDestroyed();
}
if (c.getLabel().equals("Next"))
{
strID = ID.getString();
strPlace = txtPlaceName.getString();
strLocation = txtLocation.getString();


String strEstablishmentType = chcEstablishmentType.getString(chcEstablishmentType.getSelectedIndex());
String strFoodsold = "";
for (int i = 0; i < chcFoodsold.size(); i++)
{
if (chcFoodsold.isSelected(i))
{
strFoodsold += "\n" + chcFoodsold.getString(i);
}
}
String strOrderDetails = "ID: " + strID + "ordered " + strFoodsold + " from a \n " + strEstablishmentType + " called " + strPlace + "\n in " + strLocation;
mAlert.setString(strOrderDetails);
mDisplay.setCurrent(mAlert);
}

}

protected void destroyApp(boolean param) {}
protected void pauseApp() {}
}