I have strange problem with `radio button`. I used `UIButton` for `radio button` and used two image `btnCheck.png` and `btnUnCheck.png` in normal case its working properly there is no problem. this is my code on button click

```
   -(IBAction)btnNextClick:(id)sender {
      UIImage* selectedImg=[UIImage imageNamed:@"btnCheck.png"];
      if ((btnILink.imageView.image == selectedImg  || btnTapeIn.imageView.image == selectedImg || btnKeraLink.imageView.image == selectedImg))
      {
        if (btnTapeIn.imageView.image == selectedImg) {
            UIImage* selectedImg1=[UIImage imageNamed:@"btnCheck.png"];
            if (!(btn18.imageView.image == selectedImg1 || btn22.imageView.image == selectedImg1)){
                [FunctionManager showMessage:@"" withMessage:@"Please Select Length" withDelegage:nil];
                return;
            }
        }
        else {
            UIImage* selectedImg1=[UIImage imageNamed:@"btnCheck.png"];
            if (!(btn16.imageView.image == selectedImg1  || btn18.imageView.image == selectedImg1 || btn22.imageView.image == selectedImg1)){
                [FunctionManager showMessage:@"" withMessage:@"Please Select Length" withDelegage:nil];
                return;
            }
        }
      }
      else {
          [FunctionManager showMessage:@"" withMessage:@"Please Select Method" withDelegage:nil];
          return;
      }
    }

```

![enter image description here](https://i.stack.imgur.com/Q3BmJ.png)

its working properly when I click on `btnNext`, if no any one item is selected then it display message. but problem is When I select the both item and go in background then I comeback in the app and click on next then it display the message, but Check box already selected. why the condition is not true in that case... 

![enter image description here](https://i.stack.imgur.com/8A9mR.png)