Prevent advancing to next (or another field) until valid/proper entry of current field
So I have a form with REQUIRED fields that cannot be left blank. Two fields in particular are important. What I'd like to have hapen is that if either of those fields is clicked/tapped/touched (and once they are active), it forces the user to input a valid entry before allowing them to move to the next or to another field. However, once a valid input is entered, they'll be free to advance to the next or another field.
Any suggestions?
By default the field is blank. The filed cannot be left blank either. So basically once the user enters that field, they need to complete it before moving on.
