>In first , i very very grateful your reply........but i don't know to do .......
>1. You and i also try the MaskedTexbox and DataBindings, after delete the MaskedTexbox data, and entry next control, but in this time, i can't leave the MaskedTexbox, it must i entry the data.........
>2. i don't know how to use Mere Mortals Framework to solve this question?
>
>Anyone try to use MaskedTexbox and DataBindings?
>
>thx~~~ thx~~~ thx~~~
In the validating or leave method, you would put something like this:

if (this.txtDateValue.Substring(0,3) == "  /")
{
    this.txtDateValue = "";
}

You will probably also have to store null to the underlying data column.