Set a delay in function Update

I want to set a delay before deactivating an object, i got most of the script except the delay, anyone can help??

function Start ()
{
    renderer.enabled = false;
}

function Update ()
{
    if (Input.GetButtonDown("Jump")) 
    {
        renderer.enabled = true;
    }

    if (Input.GetButtonUp("Jump")) 
    {
            //Set up delay here
        renderer.enabled = false;
    }
}

        function Start ()
        {
            renderer.enabled = false;
        }

        function Update ()
        {
            if (Input.GetButtonDown("Jump")) 
            {
                renderer.enabled = true;
            }

            if (Input.GetButtonUp("Jump")) 
            {
               DisableRendererWithDelay();

            }
        }

    function DisableRendererWithDelay() {
    yield WaitForSeconds(5);
   renderer.enabled = false;
    }

You could use WaitForSeconds, but you have to call this function in a Coroutine.

More information can be found here: Overview: Coroutines & Yield