WindowHandler.CheckIDs C# (CSharp) Method

    public void CheckIDs()
    {
        this.lastTime = Time.time;
        int highest = -1;
        ArrayList remove = new ArrayList();
        foreach(DictionaryEntry entry in this.list)
        {
            int id = (int)entry.Key;
            if((Time.time - (float)entry.Value) > this.removeTimeout)
            {
                remove.Add(id);
            }
            else if(id > highest)
            {
                highest = id;
            }
        }
        foreach(int id in remove) this.list.Remove(id);
        this.freeID = highest+1;
    }