Can't refresh datagridview with bindingsource

Question

Goal:
Once clicking on add or delete button, the datagridview should be refreshed with the latest data from document.

Problem:

The datagridview can't be refreshed after making changes by deleting or adding new data.

I'm using binding source that is linked with datagridview's datasource.

I tried everything with different solution and read advise from different forum but still I can't solve this problem.

I also tried using these syntax "BindingSource.ResetBindings(false)", "BindingSource.Refresh()" etc but no result.

Links below:

http://stackoverflow.com/questions/2348593/how-to-refresh-a-bindingsource

http://www.eggheadcafe.com/community/aspnet/2/10114324/datagridview-refresh-from-another-form.aspx

http://blogs.msdn.com/b/dchandnani/archive/2005/03/15/396387.aspx

http://bytes.com/topic/c-sharp/answers/812061-problem-refresh-datagridview