Using GUI buttons to play animations

Currently I'm trying to create a GUI button that, when a user clicks on it, the player character will immediately start attacking something (i.e., play its attack animation).

I've looked at the Command field, and have tried many things, like

Command = "$globalPlayer.playThread(0, \"attack\");";

but that crashes Torque. (I've declared $globalPlayer in my player.cs file as my player character.)

I've also tried making a playAttackAnimation() in my player.cs file and my .gui file, and having the Command field call it, but the console.log says the function is never found.

Could anyone give a hint as to how to make a GUI button play an animation?

Thanks! :)

-Karen