Attach different affects to 2 planes


I've a problem when I want to attach an effect to a plane and another to another plane.

To attach a day/night and dusk/dawn effect to a building, I create planes with transparency (I know it's necessary to have a plane for each parameter)
On the first plane, I want to attach the dusk/dawn effect and on the second, the day/night effect.
The problem : I can't attach a new effect in blender. All change on an effect for a plane change the effect to the other plane. I can't create a new effect. It's like if there is only one effect for the two planes.

My question is : after create and attach an effect to a plane, how create and attach a new effect to another plane. There is no button "new effect" or similar….

I hope you undersand. It's a little difficult to explain this problem. :)
I answer myself

It's only a visual problem in the "effect Options" menu in Blender. Only one effect is shown.
But when the oblect is exported, all is ok and the different effect are ok !