Question : Make connection from instance to interface

I have created a NSString variable in my .h file here is the code

@interface GatheringResult : NSObject {
     IBOutlet NSString *sai_transactionnumber;
}
- (IBAction)ResearchEntry:(id)sender;
@end

but when i try to link my instance to a text field, it make nothing
what i did wrong

Answer : Make connection from instance to interface

Probably, you need:
IBOutlet UITextField *sai_transactionnumber;

If you have a text field and need to get to it from your code, you add UITextField variable as an outlet.

You can add NSString too, I do not know what exactly you do.