View not getting displayed using Nib file

[iPhoneDeveloper]

Hi,

I have an existing view in which i want to add another view which is getting created via a NIB file.Cod i am using is

MyController *controller=[[MyController alloc]initWithNibName:@"MyController" bundle:Nil];
[self.view addSubview:controller.view];

I can see the controller "loadview" and "viewdidload" method getting called.But there is no change on the screen.
I am really struck here and not able to proceed further.Please help.

Thanks,