Raycasting and GUI

Hey guys, So I'm making a city builder at the moment using raycasting a gui elements.

To keep this simple, I have a barracks building, when the player clicks the barracks, a gui button appears that spawns a soldier when clicked, however, I have coded it so that when the player clicks away from the barracks (i.e. on the ground) it clears this button.

So right now I have an issue where when I click on the "Train Soldier" button, I'm actually clicking out of the barracks, and not pressing the button.

Any ideas on how to bypass this?