Set background color of a <div> element when the <div> element or any child elements loses focus:
The focusout event occurs when an element (or any elements inside it) loses focus.
The focusout() method attaches a function to run when a focusout event occurs on the element, or any elements inside it.
Unlike the blur() method, the focusout() method also triggers if any child elements lose focus.
Tip: This method is often used together with the focusin() method.
|function||Optional. Specifies the function to run when the focusout event occurs|