public void AddLine()
    {
        LineContentManager lCM = Instantiate(linePrefab, this.transform).GetComponent <LineContentManager>();

        lineList.Add(lCM);
        lCM.SetNumber(lineList.Count);
    }
 public void RemoveLine()
 {
     if (lineList.Count > 0)
     {
         LineContentManager lCM = lineList[lineList.Count - 1];
         Destroy(lCM.gameObject);
         lineList.RemoveAt(lineList.Count - 1);
     }
 }