Horse Caller Button on Inventory! HELP

[ntgaming 0]

Hello everyone! 

       First excuse me my bad English, this is so for the reason that I'm Brazilian, resident inside.
       I have a question about PYTHON, in fact, a problem. I put in my inventory a new button that I would use to invoke the horse, but the code that was left in the tutorial, did not explain how to put            up to get the horse. the button is there, with icon and all, but when I click nothing happens. someone knows how to create the button to invoke the horse? I would really appreciate now. Thanks and have a Happy New Year!

[Pisti95 132]

I wrote as button.

Link:  http://www.4metin2.com/topic/283-python-horse-summon-with-inventory-button/