You can use a state machine. It can be as simple as having a "printable=1" key:

if ( $printable )
{
    # print it printable
    print "<h1>RESULTS</h1>";
}
else
{
    print "<p>Welcome to the calling page</p>\n";
    print "<a href=xxxx?printable=1 target=\"_blank\">Click for Printa
+ble version</a>";
}
[download]

untested, may contain several syntax errors.