Location Api

I am using following code to get coordinates of location in gps.
On emulator in netbeans it shows me output as

2.0 2.0
but on real mobile it doesrnt give me any help:

package com.tutorial;
import javax.microedition.location.*;
import javax.microedition.lcdui.*;
import javax.microedition.midlet.*;
//import net.jscience.util.MathFP;
public class HelloMap
extends MIDlet
implements CommandListener {
private Form mMainForm;
public HelloMap() {
mMainForm = new Form("Hello map");
mMainForm.append(new StringItem(null, "Hello, map!\n"));
mMainForm.addCommand(new Command("Exit", Command.EXIT, 0));
mMainForm.setCommandListener(this);
}
// First Set criteria for selecting a location provider:
Criteria cr= new Criteria();

public void startApp() {
cr.setHorizontalAccuracy(500); // accurate to 500 meters horizontally

try {
// Now get an instance of the provider
LocationProvider lp= LocationProvider.getInstance(cr);

// Request the location, setting a one-minute timeout
Location l = lp.getLocation(2);
Coordinates c = l.getQualifiedCoordinates();

if(c != null ) {
// Get coordinate information
double lat = c.getLatitude();
double lon = c.getLongitude();

mMainForm.append(""+lat+""+lon);
}

} catch (Exception e) {
}
Display.getDisplay(this).setCurrent(mMainForm);
}

public void pauseApp() {}

public void destroyApp(boolean unconditional) {}

public void commandAction(Command c, Displayable s) {
notifyDestroyed();
}
}



Please help.