Need help in forcing the user to keep the prev format and not change it.

[pedie]

how can I not allow user to remove date from "10/1/2010 9:15 PM" format....current code in cell in date & " " & time. Some user edit the time and in the mean time remove the date and leave only the time which I dont want to happen.

Allow user to change the date and time too but always force user to keep it in 9/1/10 12:30 PM format.

If we can achieve this with the help of data validation then it would be better:
Thanks

 

[pedie]

I read this link but not sure how to make it workhttp://www.contextures.com/xlDataVal07.html#Space

I'm sure some1 can help..could you easy for you