NSString *urlString =[NSString stringWithFormat:@"http://api.stackoverflow.com/1.0/questions?tagged=iphone & key=%d",key1];
NSURL *url = [NSURL URLWithString:urlString];
NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url
cachePolicy:NSURLRequestUseProtocolCachePolicy timeoutInterval:60.0];
[request setHTTPMethod:@"POST"];
[request setValue:@"text/json" forHTTPHeaderField:@"Content-Type"];
[request setValue:@"text/json" forHTTPHeaderField:@"Accept"];
NSError *error ;
NSData *response = [NSURLConnection sendSynchronousRequest:request returningResponse:nil error:&error];
NSString *json_string = [[NSString alloc] initWithData:response encoding:NSUTF8StringEncoding];
NSLog(@"jsondata=%@,%@",json_string,response);
2011-02-11 12:01:16.653
mystack[1946:207] jsondata=,(null)
thanks for helping me here is the answer
the code that i have to change..