'NSUTF8Encoding' Undeclared?

[Vermillion]

Hi guys, I'm reading this book called "Programming Objective-C 2.0" by Stephen G. Kochan. In chapter 20, he put the following snippet:

#import <Foundation/Foundation.h>

int main (int argc, const char * argv[])
{
    NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
	
	NSDictionary *glossary =[NSDictionary dictionaryWithObjectsAndKeys:
							 @"Class declared so other classes can be inherited from it.",
							 @"abstract class",
							 @"To implement all the methods defined in a protocol.",
							 @"adopt",
							 @"Storing an object for later use.",
							 @"archiving",
							 nil
							 ];
	
	if([glossary writeToFile:@"glossary" atomically:YES encoding:NSUTF8Encoding error:nil] == NO)
	{
		NSLog(@"Save to file failed.");
	}
	
    [pool drain];
    return 0;
}

But when I try to compile it, it says NSUTF8Encoding is undeclared. I have copied the example twice with no luck. Can someone tell me a good fix for this issue? I don't want to skip the chapter because it's quite important.

EDIT: It also says glossary may not respond to the writeToFile:atomically:encoding:error: method. WTF.

[Vermillion]

Sorry for the double post, but for those wondering, it was a mistake from the book. The specified method is not that big, and I solved this buy checking the errata for the book.