Out of Hours Charging

[DTMark]

Hi

We want to set up an out of hours charging tarriff (we're a web design company as opposed to hosting company, so support is intended for office hours only in normal circumstances)

Clients can submit a ticket any time however what we'd like to do is to have a choice (radio buttons) which says something along the lines of:

- I will wait for a response during office hours
- I desire a response outside office hours, and understand that I will be billed £250.00 + VAT for this

If the Client selects the second option they have to type the words "I AGREE" into a box so there is no scope for misunderstanding later, since the out of hours charges are quite steep.

We can add custom fields, I'm guessing we need to add some Javascript to check the status of the I AGREE box and the radio buttons to make sure the form is valid - does this sound feasible, has anyone done anything like this?

Thanks,
Mark