ask about how to use OnMouseOver (OnMouseDown, OnMouseExit) to a gameobject (model)

Unity Engine
1

Hi,
I tried to use OnMouseOver to a 3D model in the game. I added a mesh collider to the machine and set the trigger active. But i can’t detect the when the mose is over the object. Can someone give me some suggustion?
Thanks!

2

I created this post in response to someone with a similar question:

http://forum.unity3d.com/threads/107760-Raycasting-Distance-Issue-(Playable-Game-Link-to-Show-Example)?p=712778&viewfull=1#post712778

3

Also if your playing on your ios device, none of these work.