This is the picture after I end task the eclipse. My Android Program has no errors, and before this problem it was all fine. It happened when I added some code into my program. It gets stuck after I click the run button. This also happens when I run my handphone for debugging the program. Other programs are all working fine, only one is stuck. When I try to remove and import it again seem there is a classes.dex file which I cannot delete, I have to restart my computer for it to allow to delete and I have to force the program to close. I have searched at this website and they said keep open the emulator but it doesn't work for me. below is the connecting coding that i added. //check internet connection private boolean chkConnectionStatus(){ ConnectivityManager connMgr = (ConnectivityManager) this.getSystemService(Context.CONNECTIVITY_SERVICE); final android.net.NetworkInfo wifi = connMgr.getNetworkInfo(ConnectivityManager.TYPE_WIFI); final android.net.NetworkInfo mobile = connMgr.getNetworkInfo(ConnectivityManager.TYPE_MOBILE); if( wifi.isAvailable() ){ return true; } else if( mobile.isAvailable() ){ return true; } else { Toast.makeText(this, "Check your internet" , Toast.LENGTH_LONG).show(); return false; } }