title: Android AlertDialog box WindowManager$BadTokenException problem
body: <p>I am using the the following code for a context menu and then if user chose delete, a dialog massage will appear.</p>
  
  <pre><code>infos.setOnCreateContextMenuListener(new OnCreateContextMenuListener(){
              //@Override
              public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
                  menu.setHeaderTitle("Context Menu");
                  menu.add(0, CONTEXT_EDIT, 0, "Edit Item");
                  menu.add(0, CONTEXT_DELETE, 1, "Delete Item");
              }
  });
  
  public boolean onContextItemSelected(MenuItem item) {
  
          AdapterView.AdapterContextMenuInfo menuInfo = (AdapterView.AdapterContextMenuInfo)item.getMenuInfo();
          final Long _id = menuInfo.id;
          //selected_row = menuInfo.position;
  
          // To get the id of the clicked item in the list use menuInfo.id
          switch (item.getItemId()) {
              case CONTEXT_EDIT:
                  addEditRes(_id);
                  break;
              case CONTEXT_DELETE:
                  AlertDialog.Builder builder = new AlertDialog.Builder(this);
                  builder.setMessage("Are you sure you want to delete?")
                         .setCancelable(false)
                         .setPositiveButton("Yes", new DialogInterface.OnClickListener() {
                             public void onClick(DialogInterface dialog, int id) {
                                 infoDataHelper.deleteRes(_id);  
                                 model = infoDataHelper.getCursor(addType);
                                 adapter.changeCursor(model);
                             }
                         })
                         .setNegativeButton("No", new DialogInterface.OnClickListener() {
                             public void onClick(DialogInterface dialog, int id) {
                                  dialog.cancel();
                             }
                         });
                  AlertDialog alert = builder.create();   
                  alert.show();
                  break;
              default:
                  return super.onContextItemSelected(item);
  
          }
          adapter.notifyDataSetChanged();
          return true;
  }
  </code></pre>
  
  <p>But as soon i am choosing the delete, it is giving the following error.</p>
  
  <pre><code>android.view.WindowManager$BadTokenException: Unable to add window -- token null is not for an application
  </code></pre>
  
  <p>What is the problem in my code?</p>