As the text boxes are "
Date
" fields, and not "
Numeric
" fields, you need to use
Custom validator
(To validate the text box values using a custom javascript code).
You can have a look
Here[
^] to see how to implement a Custom Validator.
Inside the custom validator javascript function, you should get the date values from the two date fields, compare them and then set
args.IsValid
= true or false.
Good luck.