I can't figure out why you are still confused by this. Just because the user fills out the form first, and then is authenticated second, does not mean that the code has to implement those steps in that order. 

## pseudocode:

if ( have user credentials )
{
  if ( credentials are valid )
  {
    redirect  # see note 1
    exit
  } else {
    record error details
  }
}

print headers

print error details
  if ( error details )

print form

[download]

Given the confusion the modal nature of your design seems to be causing you, I would recommend making the form and the validation different scripts.

note 1: make sure that your landing page inspects the credentials, etc. In your code you are redirecting to a URL with the username, etc. embedded. Obviously the landing page needs some sort of authentication too.

In reply to Re^9: Redirecting values from 1 script to another by fishbot_v2
in thread Redirecting values from 1 script to another by Nik

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.