Hi Boris,

PromptChar = ' ' is the correct way. Notice that I am setting it to a single space character, not an empty char/string. I also tried (char)0 and that worked, as well.

In your example, here, it looks like you are just entering integers. Is that the case? Or did you just not list the decimal point because it's not relevant to the issue? If you are just editing integer values, anyway, then maybe a better solution would be not to use a Mask at all. After all, what is the Mask giving you? All it really does it limit the length of the string, and you could just as easily do that by setting MaxLength on the column. It also prevents the user from typing in a letter or other non-numeric character, but you could validate this in a number of other ways, like handling the BeforeExitEditMode or BeforeCellUpdate event and doing validation there.