Submit Data and Redirect To Paypal - redirect

Question

I have a form on my website. When this form is submitted ( to the same page ) , a file is uploaded and all the details in the form are entered into a database. Next thing is we need to redirect to paypal for payment. Whats the best way to design this?
My form has the following fields:
name, email, password, attached file
PayPal Submission form is like this
<form id="frm_paypal" action="https://www.paypal.com/cgi-bin/webscr" method="post">
<input type="hidden" name="cmd" value="_s-xclick">
<input type="hidden" name="hosted_button_id" value="JDEC8Q72KAYRN">
<input type="submit" src="https://www.paypalobjects.com/en_US/i/btn/btn_buynowCC_LG.gif" border="0" name="submit" alt="PayPal - The safer, easier way to pay online!">
<img alt="" border="0" src="https://www.paypalobjects.com/en_US/i/scr/pixel.gif" width="1" height="1">
</form>
Note:
I am not being able to redirect to paypal with post data using header('paypalurl')

Answer 1

Ya you cant redirect using header() because you've already sent headers to the page.
So basically, what you can do is gather all the data you need to save in the DB and when they click 'Sign Up' send them to a 'Confirmation Page' that says "Please confirm what you entered, press Pay Now when ready". So it adds an additional click, but its a familiar flow for most checkout processes, so it shouldnt be inconvenient really.

Answer 2

i know this question is old, but maybe it helps someone who comes across this like myself...
alternatively, you do not output any form fields but do a header redirect like so
header('location: https://www.paypal.com/cgi-bin/webscr?'.http_build_query($varsToSendtoPaypal).'');
i know in the paypal documntation it is supposed to be a post request, but I have - as yet anyway - not have had any problems doing it this way (and it saves that additional click)
just a suggestion though