The following seems to work correctly:

sub check_card
{
    my $cardno = $card->get();

    if    (length $cardno == 0)
    {
        error_no_card();
    }
    elsif (length $cardno >  0)
    {
        $mw->Label
        (
            -text  => "\nChecking Account Details for '$cardno'.\n Ple
+ase Wait......\n",
            -width => 54,

        )->pack();

        $mw->update;

        my $exists = check_in_SQLStore($cardno);

        print "We got nothing\n" unless $exists;
    }
}

[download]

That is, call $mw->update; immediately after creating the label.

See, for example, the recent thread Perl/Tk window contents disappear when obscured then revealed.

Hope that helps,

Athanasius <°(((>< contra mundum Iustus alius egestas vitae, eros Piratica,

In reply to Re: Tk won't output until finished by Athanasius
in thread Tk won't output until finished by packetstormer

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.