how to create login page validate with web server in iphone

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C

Mobile

iPhone

Objective-C

I am new in iphone.i want to create login page.i want to check username and password with web server data.

Am using folling code. where am wrong.
-(IBAction)LoginBtnClick:(id)sender
{
if([usernameTxt.text isEqualToString:@""] || [passwordTxt.text isEqualToString:@""] )
{
[self alertStatus:@"Please enter both Username and Password" :@"Login Failed!"];
}
else
{
NSString *respstring = [[NSString alloc]initWithData:jsonData encoding:NSUTF8StringEncoding];

SBJsonParser *objSBJsonParser = [[SBJsonParser alloc]init];

NSDictionary *respDict = [[NSDictionary alloc]initWithDictionary:[objSBJsonParser objectWithString:respstring]];
// NSLog(@"respDict: %@",respDict);

NSDictionary *json = [[NSDictionary alloc]initWithDictionary:[respDict valueForKey:@"jsonpost" ]];
NSString *string= [NSString stringWithFormat:@"http://192.168.10.28:5000/wsserver.php&Username=%@&Password=%@",usernameTxt.text,passwordTxt.text];
NSLog(@"%@",string);
NSURL *url = [NSURL URLWithString:string];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url];
[request setHTTPMethod:@"POST"];


//[request setValue:postLength forHTTPHeaderField:@"Content-Length"];
[request setHTTPBody:[[NSString stringWithFormat:@"username=%@&password=%@",usernameTxt,passwordTxt] dataUsingEncoding:NSUTF8StringEncoding]];

[request setValue:@"application/x-www-form-urlencoded" forHTTPHeaderField:@"Content-Type"];
[request setValue:@"UTF-8" forHTTPHeaderField:@"charset"];
[request setValue:@"XMLHttpRequest" forHTTPHeaderField:@"X-Requested-With"];



NSURLResponse *response;
NSError *err;
NSData *responseData = [NSURLConnection sendSynchronousRequest:request returningResponse:&response error:&err];
NSLog(@"responseData: %@", responseData);
NSString *str = [[NSString alloc] initWithData:responseData encoding:NSUTF8StringEncoding];
NSLog(@"responseData: %@", str);
NSString *str1 = @"1";
if ([str isEqualToString:str1 ])
{

UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Successfully" message:@"" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];

[alert show];
[[self navigationController]pushViewController:snsViewController animated:YES];
}
else
{
UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Try Again" message:@"" delegate:self cancelButtonTitle:@"Try Later" otherButtonTitles:@"Call", nil];
alert.tag = 1;
[alert show];
}
}
}