Add fields to an admin page with a module?

Is there an easy way for me to add extra fields to an admin page such as the quote/proposal page? I am trying to figure out the best way to add a reminder field as a date for when I should be reminded to contact a client if I have not heard back from them in regards to the quote?

The actual date could be stored in my own database table I just need help adding the field. Any information that would get me going in the right direction is greatly appreciated. Thanks!

if this is purely as a reminder, have you thought about using a widget in the admin area?

http://docs.whmcs.com/Widgets

I use a widget that shows forthcoming renewals and I can use it to remind myself to check that the invoice was created... e.g it takes the next due date, subtracts 14 days, and so I can see the date on which the invoice should be generated by the cron.

perhaps you could use one of the existing quotes dates, datesent or validuntil, to calculate your reminder date - e.g 7 days after datesent or 7 days before validuntil.

perhaps you could use one of the existing quotes dates, datesent or validuntil, to calculate your reminder date - e.g 7 days after datesent or 7 days before validuntil.

Good idea, that get's me at least half way there It would be nice to be able to set a date though as some clients might say something like they have a shareholder meeting on some date next month where they will discuss the quote and then I want to be reminded to call them 2 days after or something like that.

Good idea, that get's me at least half way there It would be nice to be able to set a date though as some clients might say something like they have a shareholder meeting on some date next month where they will discuss the quote and then I want to be reminded to call them 2 days after or something like that.

hmm... if they were clients, you could use a custom client field for that and make it admin only - but as quotes can be sent to non-clients, that's not a solution.

would it be an option to use the Admin Only Notes facility of the quotes? either to simply enter a text reminder to yourself which you can display in the widget output, or maybe pull a date from the admin text and separate it as a reminder date ??

That could work but I feel like they are just solutions that won't do the job, it wont make it easier. What I think I might do is just use javascript and the adminAreaFooterOutput hook to add the field and then another hook or javascript to store the value.