Moving a set of pictures in an array in two directions

Unity Engine
1

I’m trying to move some pictures in an array forward with one UI Button then reverse with another button.I have it working somewhat, but when I reverse the numbers don’t work right…if going forward to the last one…if its the number 4 in the array…hitting the reverse button , should bring up picture number 4…instead it starts with 1,then 0, then -0…here’s my script

// cycle pictures forward and reverse
// using Unity 4.6

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

public class Back_Forth : MonoBehaviour
{

    public Sprite[] fish;
    //public TextAsset[] myAssets;
    public static int FWcount = 0;
    public Image FishImage;
    public Button forward;
    public Button back;
    //public Text myText;

    void Start ()
    {
        FishImage.sprite= fish[FWcount];
        //myText.text=""+myAssets[FWcount];
    }
   
    public void ForwardFish ()
    {
        if(forward)
        {
            FWcount  = FWcount +1;
            FishImage.sprite= fish[FWcount];
            //myText.text=""+myAssets[FWcount];
            if(FWcount>=2)
            {   FWcount = 2;  }

        }
    }

    public void BackFish ()
    {
        if(back && FWcount>=0)
        {
            FishImage.sprite= fish[FWcount];
            //myText.text=""+myAssets[FWcount];
            FWcount  = FWcount -1;
            if(FWcount<0)
            {   FWcount = 0;  }
        }
    }
   
}
2

You need to set the sprite after you calculate the number. Change it to:

public void ForwardFish ()
    {
        if(forward)
        {
            FWcount  = FWcount +1;
            //myText.text=""+myAssets[FWcount];
            if(FWcount>=2)
            {   FWcount = 2;  }
             FishImage.sprite= fish[FWcount];
        }
    }

    public void BackFish ()
    {
        if(back && FWcount>=0)
        {
            //myText.text=""+myAssets[FWcount];
            FWcount  = FWcount -1;
            if(FWcount<0)
            {   FWcount = 0;  }
            FishImage.sprite= fish[FWcount];
        }
    }
3

Thanks a lot…I guess order is everything