modification of perl tk code

Hi...
i have this perl tk code to connect to the database.
it will print the output of the search result($dir)on to the gui($text).
the problem i faced now, is that the "$dir" could not be printed out as what is being stored in the db.
instead it print out "0".

how do i modify this code.

Thanks....

Perl tk code

  $dbh = DBI->connect( 'dbi:mysql:rvsi')||
   die "Cannot connect to database: $dbh->errstr\n";
   $job=$entry->get;
   $date=$entry1->get;
   $sql = 'SELECT dir FROM tray WHERE job = "$job" AND date = "$date"';
   $sth = $dbh->prepare($sql) || die "Couldn't prepare: $dbh->errstr\n";
   $dir = $sth->execute;
   $slt="Tray Report";
   $text->delete('1.0','end');
   $text->insert('1.0',"\n\n Tray Report Result\n\n");
   $text->insert('end',"Job specification: $job\n\n");
   $text->insert('end',"Date: $date\n\n");
   $text->insert('end',"Directory path: $dir\n\n");
   print "$dir\n"