Full disclosure - I'm not total novice so any help would be appreciated but simple help for dummies will be extra appreciated :)

I'm creating a form in an html page. It needs to link up with a payment gateway and forward the entered information (I'm currently using the method="post" and that's all working fine), but I also need to collect the information and have it sent to a nominated email address (I'm currently using a sendmail.php action).

I have managed to make both work separately, but not together for the obvious reasons.

Is there a way to achieve both functions off the same form submission? And if so what is it?

I think tats possible...

Add to the onclick attribute of the submit button, two functions in which u can set the form action as the programs u have coded in php.

The functions must be written in JavaScript..

I can not provide you with a working code right now, but this should be possible. It's all a matter of some PHP magic ;)

Look around the net for PHP functions to send emails (There's a build in function) and figure out how to do both things at the same time. One good advice though, remember to sanitize your input! You don't want to give a possible attacker free access to your payment options or anything like that.