Extend the file form5.html so that it does not permit the form to be submitted when neither a standard nor a deluxe model have been selected.

You can find a discussion of this activity at the end of the unit.

It can be very annoying to users to receive many different error messages from the same form (i.e. three or four alerts all appearing one after the other).

For example, in the previous colour model form, if the screen were as follows:

the user would have to respond to the following sequence of alerts:

Amend the code so that an alert is only displayed for the first error encountered.

You can find a discussion of this activity at the end of the unit.