syntax error before 'AT_NAME' token

just starting to learn xcode after having used vim and the terminal for years.

the worlds simplest app, like a cocoa hello world, and i get a syntax error before 'AT_NAME' token on line 1 of this file
#import "BeepController.h"

@implementation BeepController
- (IBAction)sendBeep:(id)sender {
    NSBeep();
}
@end

presumably because there is no @end in this header file but there is
#import <Cocoa/Cocoa.h>

@interface BeepController : NSObject {
}

- (IBAction)sendBeep:(id)sender:
@end

there must be some macfags here who know the score

lol i just saw it, a semicolon instead of a colon. fucking obj-c