NSString is NULL
hiiii freinds please any guys say me why str is NULL i will be creasy 

NSString *strData = @"issam  bey"   ;
	
   	NSMutableData *objNSData = [NSMutableData dataWithData:[strData dataUsingEncoding:NSISOLatin1StringEncoding]];
	
	
    objNSData = [objNSData EncryptAES:@"12345678901234561234567890123456"];
	//NSString* decryptedStr = [[NSString alloc] initWithData:objNSData encoding:NSASCIIStringEncoding];
	
	NSString *str=[[NSString alloc] initWithData: objNSData encoding:NSUTF8StringEncoding];
	
	NSLog(str);
NSString is NULL
===

hiiii freinds please any guys say me why str is NULL i will be creasy 

NSString *strData = @"issam  bey"   ;
	
   	NSMutableData *objNSData = [NSMutableData dataWithData:[strData dataUsingEncoding:NSISOLatin1StringEncoding]];
	
	
    objNSData = [objNSData EncryptAES:@"12345678901234561234567890123456"];
	//NSString* decryptedStr = [[NSString alloc] initWithData:objNSData encoding:NSASCIIStringEncoding];
	
	NSString *str=[[NSString alloc] initWithData: objNSData encoding:NSUTF8StringEncoding];
	
	NSLog(str);