How to destroy the Previous instance of prefab at runtime

hi,
I created a gameobject and made it as prefab. I was trying to instantiate the prefab(gameObject) whenever there is touch response but at the same time i also wanted to delete the previous instance of prefab as soon as the new instance was created .

for eg:- whenever i will touch the screen, a new instance will be created. again i will touch the screen, another new instance will be created but also at the same time previous instance will be destoyed.

I managed to do till the creation of instance through touch but was not able to think a way of destroying the previous instance.

I was trying it to do it by Array , but i was not able to pinpoint the code.

Can someone help me. Will be really appreciated…
Language should be in c#

Thanks

private GameObject activePrefab;

private void CreatePrefab() {
    if(activePrefab != null) Destroy(activePrefab);
    activePrefab = Instantiate(YourPrefab, YourTouchPosition, Quaternion.identity) as GameObject;
}