Some coding needed for my website!

I have an existing website that needs to have 2 small features added PHP coding! 1) When a user on the site presses the button to continue to the payment process, a file with a specific name needs to be created on the server. The name of the file will be the main email address the user specifies on the page, with a .htm extension at the end. The only data that would go into this file is if the user provides us with an additional e-mail. Then that would be written as text inside this file. But if they don't provide an additional e-mail. Then there doesn't need to be any data in that file. The file is really just there so that we can keep record of our clients, in other words there will be one file for each client. 2) At the same time, an email must be sent to a fixed email address that we will specify (we can hardcode this into the program ourselves…. just put a generic e-mail name in that spot). The email also must be sent "behind the scenes", without the user knowing about it. Basically it will be sent to our support department as a notification that a sale has been made. Let me know if you have questions, thanks! -Robert Harris