I know what you and a few others below are saying about the user interface issue but this seems to be a data integrity issue and sounds like it is meant to solve a serious problem; mixing up medical records and making sure a data set for a study isn't corrupted. Depending on the situation this is a problem that kills a lot of people.

It's still not a perl question but with JS you can probably solve it in a few ways that the casual (non-technical, one-time) user couldn't get around while still being able to submit the form. Don't write the form at all unless JS is on and do some primitive checksum via onkeypress that writes it to a JS created hidden input field/node so you know that at least X characters were pressed in the same order in each field (or clear both and start over) and it wasn't a cut and paste. Then send the form and checksum data to perl on submit for validation.

In reply to Re^2: prevent pasting into a CGI textbox by Your Mother
in thread prevent pasting into a CGI textbox by nosbod

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.