ActionButton seems not working with Apache Click 2.3.0

[easydoor958]

When i put in a search form an ActionButton which allows user to clear values 
in 
the fields to reset criterias. 
I put this code 
ActionButton clearButton = new ActionButton("Effacer les critères", this, 
"onClear"); 
... 
    public boolean onClear() { 
        formSearch.clearValues(); 
        return true; 
    } 
and when i click on the button, nothing happens 

I change ActionButton by an ActionLink and it works well ! Why ?