#!/usr/bin/perl
use CGI qw(:standard);
use strict;

my $cgi = CGI->new;
print $cgi->header;
if ($cgi->param("name") ne "") { print "Welcome " . $cgi->param("name") }

##</code><code>##

<form method=post action=yourscript.pl>
<input type=text name=name>
<input type=submit name=submit>
</form>