Animation path of text boxes - Variable

Hello all,

 

maybe somebody of you can help me. 

I want to create a presentation with some animation but it still doesn't work. 

I try to explain my problem and as an attachment you can find the storyline project. 

At this page the learner should click the first box. 

The second box should slide a little bit down and between the two boxes a third box (with explanation) should appear.

Okay, this I created. But the thing is. The learner should click the second box and a fourth box should appear. The third box should eclipse. And the second box should get back at the first place of it...

It sounds a little bit complicated but maybe somebody know this situation and can help me. 

I guess I should solve the problem with a "Variable" but I don't know how.

 

Thanks in advance for your help, guys!

Greetings!