InputField's OnEndEditting: Triggered when input (click, touch, etc) on other area rather than InputField.

Hi all, I have a little problem when using InputField. I know there are two delegate "OnValueChange" and "OnEndEditting". I want the user to input text and press "done" on iPhone's default keypad when finish to trigger action. It seems OnEndEditting exactly works for this situation. But as I deploy it on my iPhone, when I am typing, if I click other area of the screen other than input field, it triggered the delegate "OnEndEditting". I mean in common sense, when clicking other area, the keypad should disappear since user don't want to input anymore.

Is there any thing I can do to prevent what happens here?