public void AddColumnChangeValue(string columName, DataGridViewValueChangeEventHandler columnvaluechangeeventhandler)
 {
     if (!ChangeValueColumns.ContainsKey(columName))
     {
         ChangeValueColumns.Add(columName, columnvaluechangeeventhandler);
     }
     else
     {
         Debug.Assert(false, "Column alredy presents in ColumnChangeValue");
     }
 }
 public void AddColumnChangeValue(IColumn columName, DataGridViewValueChangeEventHandler columnvaluechangeeventhandler)
 {
     AddColumnChangeValue(columName.Name, columnvaluechangeeventhandler);
 }