Getting cust. email via inputbox function help

Here is what I am attempting to do:
1) Get a customers email via a VB inputbox when they sign up for a class (using onSubmit, I call a function called getEmail)
2) Take that email that they submitted and send an email to it reminding them they signed up. I use another asp page to send the email, so I am trying to retrieve the email from the function…how do I do that??

Here is my code (not all of it):

Function getEmail()
Dim subEmail
Dim submitEmail
submitEmail = inputbox("Enter Email...")
subEmail = document.all.submitEmail.value
End Function

The email page:
NOTE: I used a form GET to call this page...

Dim objMail
Dim sentto
Set objMail = Server.CreateObject("CDONTS.NewMail")
objMail.From = "techsupport@blah"
objMail.Subject = "You signed up for an AOA class"
objMail.To = Request.Form("subEmail")
objMail.Body = "You have signed up for the following AOA class:" & vbcrlf&_ vbcrlf&_

….and so on….

I know you’ll probably look at this and say WTF, but I’m new at this, so any help is appreciated.

Thanks for your time,
woohouz

I'm sorry, I meant to put down that I was using POST instead of GET. Also, I'll try and explain it in more detail......
I'm trying to run an online class. When the user checks the class they want and then click "submit", a function call signs them up by adding them to a mySQL DB. At the same time, I want to be able to capture their email (thru that inputbox), take that email they input, and use it to automatically send them a reminder that they had signed up. So I was trying to run two functions when the click "submit" (onclick="function1();function2())....the first function is the updateDB, the second is the getEmail. All i guess im trying to figure out is how to get the email from the function of my 1st asp file, into my email asp file. I hope this makes a lil more sense, and thank you for all your help.

Sean