title: Show UIAlert if UITextField is empty
body: <p>All I want to do, If there is nothing on <code>UITextField</code> , application will show an alert. I don't understanding what's wrong I'm doing. here is my code:</p>
  
  <pre><code>- (IBAction)Calculate:(id)sender {
      /*If there is nothing on textfield, it will show an alert*/
  
      if ([addtake.text length] &amp;&amp; [Subtake.text length] == 0) 
      {
  
              UIAlertView *myAlert = [[UIAlertView  alloc]initWithTitle:@"Alert"message:@"Empty   TextField not allowed" delegate:nil cancelButtonTitle:@"Okay" otherButtonTitles: nil];    
              [myAlert show];
      }
  
      else{
  
              NSString *Adding =[addtake text];
              NSInteger number = [Adding intValue]; /*Converting String to int*/
              NSInteger new = 5 + number;
              NSString *newString = [NSString stringWithFormat:@"%d",new];
              [myAdd setText:newString];
              /*Subtruct*/
              NSString *Subtruct =[Subtake text];
              NSInteger SubNumber = [Subtruct intValue];
              NSInteger newSub = 10 - SubNumber;
              NSString *newSubString = [NSString stringWithFormat:@"%d",newSub];
              [mySub setText:newSubString];
  
              [addtake resignFirstResponder]; 
              [Subtake resignFirstResponder];        
        }
    }
  </code></pre>