About a required inputfield....

Hi, everyone...

I have a question...

I make a bsp page which has one requried <htmlb:inputField> and

one back <htmlb:button> for returning a previous page.

As you know, when some event is triggered, required inputfield say that "please check required field".

But, I wanna to back a previous page when I click a back button.

I wanna have a button as ABAP exit button .