How to make a slider value change by clicking on it

I want to have a slider that, when you left-click on it, adds 1 to the slider value, and when you right-click on it, subtracts 1 from the slider value. I tried attaching a script to the slider with a GetMouseButtonDown input on it, but the slider doesn’t respond to the mouse clicks the way a normal game object does.

Does anyone have any suggestions for how I can do what I’ve described above?

Four years later:

public class ToggleSliderByClick : MonoBehaviour, IPointerDownHandler {
            private Slider _slider;
    
            private void Start() {
                _slider = GetComponent<Slider>();
            }
    
            public void OnPointerDown(PointerEventData eventData) {
                switch (eventData.button) {
                    case PointerEventData.InputButton.Left:
                        DoActionLeftCLick();
                        break;
                    case PointerEventData.InputButton.Right:
                        DoActionRightClick();
                        break;
                    case PointerEventData.InputButton.Middle:
                        DoActionMiddleClick();
                        break;
                }
            }
        }