Hi!

I must to set a button with a css class when it has focused, but I don't know what to do it because it doesn't render like an input and if I try something like this, doesnt' works.
.colorBox:focus{
background-color: blue;
}
This is my button:
<ext:Button ID="btnColor" runat="server" Cls="colorBox" FieldLabel="Color" 
      Width="40" MenuArrow="false">
          <Menu>
               <ext:ColorMenu>
                     <Listeners>
                           <Select Handler="Color.setValue(color);" />
                     </Listeners>
               </ext:ColorMenu>
          </Menu>
</ext:Button>
How can I detect focus and change it with JS, or something?