How to assign callback function to Slider.onValueChanged

Hi all,
in the following script I’m trying to assign a callback function to 4.6 UnityEngine.UI.Slider.onValueChanged to do something in this OverSlider class which attached to a UnityEngine.UI.Slider. The documentation doesn’t give a hint and I didn’t find any examples.
Could you please tell me how to change the two commented lines?

Thank you.

using UnityEngine;
using System.Collections;
using UnityEngine.UI;

public class OverSlider : MonoBehaviour {

	Slider slider;

	float value = 0f;

	void Awake () {
		slider = gameObject.GetComponent<Slider> ();
		slider.onValueChanged = A(); ///////// HOW DO I ASSIGN HERE?
	}

	void Update () {

		value = slider.value;
	}

	void A(Slider.SliderEvent se) ///////// HOW DO I DECLARE THIS?
	{
           // ...
	}
}

And the fired error is:

Assets/Scripts/OverSlider.cs(14,41): error CS1501:
No overload for method 'A' takes '0' arguments

And if I get rid of parentheses:

Assets/Scripts/OverSlider.cs(14,24): error CS0428:   
Cannot convert method group 'A' to non-delegate type 'UnityEngine.UI.Slider.SliderEvent'.
Consider using parentheses to invoke the method

Try

slider.onValueChanged.AddListener(ListenerMethod);

public void ListenerMethod(float value)
{
}

Define a function that responds to the valueChanged event

void valueUpdate()
    {
        float sliderValue = mySlider.value;
        // ...
    }

…and set it as a delegate in your Start function

void Start() {
mySlider.onValueChanged.AddListener(
            delegate { valueUpdate();}
            );
}