How do I set cell to blank in a Combo box column at a datagridview

I have a DataGridView that contains one ComboBox column. the datagridview gets data from a table. the combo box has datasource from another table that contains two columns, one is ID and the another is name. I set the ID field as the combobox valuemember and set the name field as the conbo box dispalymember. everything works fine. the problem is that if a cell originally is blank. I select a value from combo box for the sell, then I find I made amistake and want to undo it. it cannot change the cell back to blank. Anyway can we do this. please help. Thanks.
JackXiangAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

x
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Automation_GuruCommented:
Hi JackXiang :

That’s a default behavior of Drop Down Box implemented by .Net.

If you really want to solve this, you have to add one more additional value in your Data Source something like Display Member “SELECT” and Value = 0/-1.

On a different note I have a query, What exactly undo means. Either you want to change the value from dropdown or don’t want to select anything. #1 you can do and for #2 directly delete the Row.

Regards,
Automation Guru

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Microsoft Development

From novice to tech pro — start learning today.