Sending post

@implementation NetWorkUtil
+(id) postRequestWithUrl:(NSString *) url andPostString:(NSString *) postString{
    return [NetWorkUtil
            postRequestWithUrl:url
            andPostData:[NSData
                         dataWithBytes:[postString UTF8String]
                         length:strlen([postString UTF8String])] // !!! Do Not Use postString.length                     
            ];
}
+(id) postRequestWithUrl:(NSString *)url andPostData:(NSData *)postData{

    [url retain];
    [postData retain];
    
    NSMutableURLRequest * postRequest = [NSMutableURLRequest requestWithURL:([NSURL URLWithString:url])];
    [postRequest setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"content-Type"];
    [postRequest setHTTPMethod:@"POST"];    
    [postRequest setHTTPBody:postData];

    [url release];
    [postData release];
    return postRequest;
}
@end

-(void) sendingPost{

    NSMutableURLRequest * postRequest = [NetWorkUtil postRequestWithUrl:mUrl
                                  andPostString:mPostData
                         ];
    [postRequest retain];

    NSOperationQueue * queue = [NSOperationQueue new];

    [NSURLConnection sendAsynchronousRequest:postRequest
                       queue:queue
                   completionHandler:^(NSURLResponse * response, NSData * data, NSError * error) {

                       //handle error if exist
                       if (error != nil ) {

                           [self onError:error];
                       }
                       else if(data != nil){
                           [self handleData:data];
                       }else {
                           [self onError:error];
                       }
                   }];

    [queue release];
    [postRequest release];
}