Why can't i use the negate command on a object mouse press event? i want to set a counter to 1 on press and change the image and set it back on release but it won't let me?

And i read in the manual that it is not available for the mouse yet and only certain commands which seems odd as im sure theres other ways to do it but it makes things a lot harder and means i need help even though it seems fairly basic so sorry for the newbie questions.

Also i wanted to modify the topic of this thread as i have asked several things now but the forum seems a bit hard to use imo as i can't find the option anyware and other things