How to show user message when used types date that is less than MinDate

Hello,

At the moment I am setting the MinDate and MaxDate properties on a RadDatePicker ​in the code behind. This works well with regard to the calendar because it is not possible to select dates outside of the range with the mouse.

However, the user may still enter dates by typing. At the moment, the default behaviour isn't great. What I would is to present the user with a meaningful message if they type a date outside of the range, preferably when the control loses focus.

I am wondering what the best way to do this is? Do I need to implement something based on <asp:CompareValidator/> or is there a better way?

Thanks in advance,

John.