Updated my code, it is just a sample program...

The updated code still won't work. The statement
    Use Tk;
is still wrong and the  $frm scalar is nowhere defined or, more importantly, initialized. See the statement
    $frm -> grid(-row=>2,-column=>1,-columnspan=>2);

Even sample programs should actually work, especially when they are being given to beginners.

Also, can you make the program run with strictures and warnings enabled?
    use warnings;
    use strict;