ImageButton1 needs to be Focused()

I have put Panel1 and Panel2 on the form. In Panel1 I have put a ColorPicker that uses an Button1.
I have also used the animationExtender to animate between Panel1 and Panel2. That is done with Button1 and Button2.
 
By default Panel1 is coming up and the ColorPicker works fine when pressing "ImageButton1" Now if we Press Button2 that will animate/take us to Panel2 and if now again press Button1 that will animate/take us back to Panel1 and press the "ImageButton1" that is our colorpicker, there will be a "Break" in the application (compilererror) that says that:
ImageButton1 doesn´t have focus
So I wonder what I need to do in the Code below. Perheps I need to have ImageButton1 focused in some way. However what is important is that I dont want to postback the whole page.
 
<asp:ImageButton ID=" ...