gistfile1.m

{
    NSString *httpBodyString = [[NSString alloc] initWithFormat:@"<?xml version=\"1.0\" encoding=\"utf-8\"?>\
<soap:Envelope xmlns:xsi=\"http://www.w3.org/2001/XMLSchema-instance\" xmlns:xsd=\"http://www.w3.org/2001/XMLSchema\" xmlns:soap=\"http://schemas.xmlsoap.org/soap/envelope/\">\
<soap:Body>\
<CheckCustomer xmlns=\"http://tempuri.org/\">\
<ABN>%@</ABN>\
</CheckCustomer>\
</soap:Body>\
</soap:Envelope>", _lastScannedCustomer.ABN];
    NSData *httpBodyData = [httpBodyString dataUsingEncoding:NSUnicodeStringEncoding];
    [httpBodyString release];
    
    NSURL *webserviceURL = ...;
    NSMutableURLRequest *urlRequest = [[NSMutableURLRequest alloc] initWithURL:webserviceURL];
    [urlRequest setHTTPMethod:@"POST"];
    [urlRequest addValue:@"text/xml" forHTTPHeaderField:@"Content-Type"];
    [urlRequest addValue:[NSString stringWithFormat:@"%d", [httpBodyData length]] forHTTPHeaderField:@"Content-Length"];
    [urlRequest addValue:@"http://tempuri.org/CheckCustomer" forHTTPHeaderField:@"SOAPAction"];
    [urlRequest setHTTPBody:httpBodyData];

   self._connectionData = [NSMutableData data]; // controller's NSData object
    [NSURLConnection connectionWithRequest:urlRequest delegate:self];
}

// then add this to your controller

- (void)connection:(NSURLConnection *)connection didReceiveData:(NSData *)data {
    [_connectionData appendData:data];
}


- (NSURLRequest *)connection:(NSURLConnection *)aConnection willSendRequest:(NSURLRequest *)request redirectResponse:(NSURLResponse *)response {
	return request;
}


- (void)connection:(NSURLConnection *)connection didReceiveAuthenticationChallenge:(NSURLAuthenticationChallenge *)challenge {
	if ([challenge previousFailureCount] > 0) {
		[[challenge sender] cancelAuthenticationChallenge:challenge];
	}
	else {
		[[challenge sender] useCredential:[challenge proposedCredential] forAuthenticationChallenge:challenge];
	}
}


- (void)connection:(NSURLConnection *)connection didReceiveResponse:(NSURLResponse *)aResponse {
    if ([aResponse class] == [NSHTTPURLResponse class]) {
        self._response = (NSHTTPURLResponse *)aResponse; // controller's NSHTTPURLResponse object
    }
}


- (void)connectionDidFinishLoading:(NSURLConnection *)aConnection {
    
    DDXMLDocument *document = [[DDXMLDocument alloc] initWithData:_connectionData options:0 error:NULL];
    DDXMLElement *rootElement = [document rootElement];
    [document release];    
    
    NSUInteger statusCode = [_response statusCode];
    if (statusCode >= 200 && statusCode < 400) {
        NSError *error = nil;
        NSString *xpath = @"/soap:Envelope/soap:Body/myns:CheckCustomerResponse/myns:CheckCustomerResult";
        NSArray *elements = [rootElement nodesForXPath:xpath error:&error];
    }
}


- (void)connection:(NSURLConnection *)aConnection didFailWithError:(NSError *)aError {
    // Deal with error
}