where to edit hide button code

i want to edit my hide button/tags but i dont know where will i go because i want to put this image in my hide button/tags.everytime we post a topic.and our member will reply to see the hidden content.pls help i dont know where will i go to edit this...

Code:

[hide]Content[/hide]

Use this code.

Sanket wrote:

Code:

[hide]Content[/hide]

Use this code.

yes i know this code my question is where do i go to edit my hide button and put my hide button image.

You wont have a image, its not possible on forumotion.

i hope u guys fix it in the future....