Hi, I have a simple form interface set up that send username and password information to a server: (working)

    NSString *postData = [NSString stringWithFormat:@"user=%@&pass=%@",[self urlEncodeValue:sysUsername],[self urlEncodeValue:password]];
NSLog(@"Post data -> %@", postData);
///
NSData* postVariables = [postData dataUsingEncoding:NSASCIIStringEncoding allowLossyConversion:YES];
NSMutableURLRequest* request = [[[NSMutableURLRequest alloc] init] autorelease];
NSString* postLength = [NSString stringWithFormat:@"%d", [postVariables length]];
NSURL* postUrl = [NSURL URLWithString:@"http://localhost/~csmith/cocoa/test.php"];
[request setURL:postUrl];
[request setHTTPMethod:@"POST"];
[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setHTTPBody: postVariables];

NSData *returnData = [NSURLConnection sendSynchronousRequest:request returningResponse:NULL error:NULL];
NSLog(@"Post data SENT & returned -> %@", returnData);

How do I handle connection errors such as no internet connection, firewall, etc. Also, does this method use the system-wide proxy settings? Many of my users are behind a proxy.

Thanks a lot!