title: use two UIPickerView in the same class
body: <p>I wrote this code for the first UIPickerView</p>
  
  <pre><code>- (void)viewDidLoad
       NSURL *url = [NSURL URLWithString:
                        @"http://localhost:8080/Data/resources/converter.country/"];
          ASIHTTPRequest *request = [ASIHTTPRequest requestWithURL:url];
          [request setDelegate:self];
          [request startAsynchronous];
        //  countrys = [[UIPickerView alloc] init];
          countrys.delegate = self;
          countrys.dataSource = self;
          countrys.showsSelectionIndicator = YES;
          countryField.inputView=countrys;
  
  
       - (NSString*)pickerView:(UIPickerView *)pickerView titleForRow:(NSInteger)row forComponent:(NSInteger)component {
          NSString *codeCity;
          codeCity=[countriesArray objectAtIndex:row];
          return codeCity;
      }
  
      - (NSInteger)numberOfComponentsInPickerView:(UIPickerView *)pickerView {
          return 1;
      }
  
      - (NSInteger)pickerView:(UIPickerView *)pickerView numberOfRowsInComponent:(NSInteger)component {
          return [countriesCodeArray count];
      }
  </code></pre>
  
  <p>And then i wanted to make another UIPickerView with cities . I wrote this </p>
  
  <pre><code> citys.delegate = self;
      citys.dataSource = self;
      citys.showsSelectionIndicator = YES;
      cityField.inputView=citys;
  </code></pre>
  
  <p>But when i click on it i have countries list . How should i change the datasource ? And how to use the default function of the UIPickerView, like numberOfComponentsInPickerView , numberOfRowsInComponent: ... with the second UIPickerView ? </p>