Hi Monks

I have a question regarding passing parameters in CGI perl scripts.

I want to pass the parameter 'oldtable' to a script from the URL, using http://www.foo.bar?oldtable=foo.
If the user doesn't pass the oldtable parameter, the script should exit.
I also want this parameter to take the value 0 when I press a separate button, called 'search'.

To do this, I have used the following code (missing out the non-relevant bits):

#!/usr/bin/perl -w
use CGI qw(:standard);
use CGI::Carp qw(fatalsToBrowser); 
if (param('oldtable')){$oldtable=param('oldtable');}
else {die 'This document must be opened with the oldtable parameter';}

print start_html(-title=>foo,
    -BGCOLOR=>bar,
    -style=>{'src'=>foo,'title'=>bar});
print start_form,
radio_group(-name=>'sortby',values=>['Sort by foo', 'Sort by bar']),p,
submit(-name=>'search',-value=>'Search'),
print end_form;
if ($oldtable==1){foo;}
if (param('search'))
{param(-name=>'oldtable',-value=>'0');
bar;
}
[download]

However, when I press the 'Search' button, I exit with the error 'This document must be opened with the oldtable parameter'. So how do I do this from within the Perl script?

TIA

CJ