Cancel users attempt to exit cell in a Datagrid

[jmcilhinney]

You should put a CoMboBox in that column and have the user select a value from a list. That way you're guaranteed of the value entered being valid. Follow the WinForms FAQ link in my signature. That page has lots of good information on various controls, and the DataGrid inparticular. It will have information on putting a ComboBox in a DataGrid.