how to connect ipad with monitor using vga adepatar?

Question

I have implemeneted ipad application and i want to connect with monitor for presentation.i have written below code .

• (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
  [window addSubview:[navigationController view]]; if ([[UIScreen screens] count] > 1) { window.screen = [[UIScreen screens] objectAtIndex:1]; } [window makeKeyAndVisible]; return YES; }

Its disply in monitor but in ipad it shows blank.

PLease help me solve this problem