UI Button click event conflicts Input.GetMouseButtonDown(0) event

Hi all
I'm newbie.
I want to create a game but i have a problem like post's title.
I develop 2 feature
- Click to screen to get mouse position and hit an object. I use Input.GetMouseButtonDown(0) and Raycast2D
- Click a button to select an item. I use Unity 4.6 UI Button.
But when i click the button, system calls both of 2 events, it calls Input.GetMouseButtonDown first then Buton click event second, so i can't use flag to fix conflict.

Please tell me how can i ignore mousebuttondown when i click on UI button?
I really need your help.

Thanks so much.

 

There are plenty of answers on how to solve this problem on the forums already. You need EventSystem.IsPointerOverEventSystemGameObject (i think thats the name)