Hi, first the easy problem, making the timer variable. You can do this by making your timer a 1 shot timer which reinstalls itself at the end of each clear_data run. To use a -textvariable as a control, you have to watch out that the user dosn't change the $sec to 0, which would mess up the timer and cause an error. So I set it that $sec cannot go below 1000. It might be good to use a Spinbox to allow the user to set $sec only to allowed values.

Here is the code.

#!/usr/bin/perl
use Tk;
use Tk::HList;
use Tk::ItemStyle;
use Data::Dumper;

my $user = $ARGV[0] || 'alex';
my $hash = {};
my ($location,$age,$use,$vendor,$feature);
my $sec = 5000; #default value
#gui variables
my ($hl,$ok,$alert);

# Making the Gui

my $mw = new MainWindow;
$mw->geometry("500x200");
my $userframe = $mw->Frame(-width=>5,-height=>10)->pack(-side=>'top',-
anchor=>'nw');
$userframe->Label(-text => "USER: $user")->pack(-side => 'left', -anch
+or => 'nw',-padx
=> 0);
$userframe->Label(-text => "Set time")->pack(-side => 'left',-anchor =
+> 'w',-padx => 0);


my $frequency = $userframe->Entry(-width=>5,-textvariable=> \$sec)
                ->pack(-side => 'left',-anchor => 'nw',-padx => 0);


my $hlistframe = $mw->Frame()->pack(-fill => 'both', -expand => 1);

$hl = $hlistframe->Scrolled('HList',
                    -scrollbars => 'ose',
                    -columns  =>4 ,
                    -header   => 1,
                    -width    => 100,
                    -command => sub {print "AAA\n";},
                    -selectmode => 'browse',
                    )->pack(-fill => 'both',-expand =>1 );



my $label1 = $hl->Label(-text => "location", -anchor => 'w');
$hl->headerCreate(0,-itemtype => 'window',-widget => $label1);

my $label3 = $hl->Label(-text => "Age", -anchor => 'w');
$hl->headerCreate(1,-itemtype => 'window',-widget => $label3);

my $label4 = $hl->Label(-text => "phone", -anchor => 'w');
$hl->headerCreate(2,-itemtype => 'window',-widget => $label4);

open_report();

$mw->after( $sec, \&clear_data);


MainLoop;

sub clear_data{

 #print "Inside clear data \n";
 read_file();
 my $path = 0;

 for my $locationkey (sort keys %{$hash->{$user}}){
 
   print "clear_data $locationkey\n";
  
  _refreshData($path,$locationkey);
 
  $path++;
  }

# make a lower bound for timer
# in case your user sets $sec to 0 
if( $sec < 1000){ $sec = 1000 }
 
# reinstall 1 shot timer for another run
$mw->after( $sec, \&clear_data);
}


sub _refreshData{

    my $path = shift;
    my $location = shift;
    print "Inside refreshdata $path | $location \n";

    my $availbl = $hash->{$user}->{$location}->{age};
    my $chk = $hash->{$user}->{$location}->{phone};
        
   if($hl->itemExists($path,0)){
        #if($hl->info(exists, $path)){
        print "itemexists ...\n";
    
    
    $hl->itemConfigure($path,0,-text=> $hash->{$user}->{$location}->{l
+ocation});
    $hl->itemConfigure($path,1,-text=> $hash->{$user}->{$location}->{a
+ge});
    $hl->itemConfigure($path,2,-text=> $hash->{$user}->{$location}->{p
+hone});

        }
        else
        {
        print "Inside else ....\n";
        $hl->add($path);
    $hl->itemCreate($path,0,-text=> $hash->{$user}->{$location}->{loca
+tion});
    $hl->itemCreate($path,1,-text=> $hash->{$user}->{$location}->{age}
+);
    $hl->itemCreate($path,2,-text=> $hash->{$user}->{$location}->{phon
+e});

        }
}

sub read_file
{
   print "Inside read file \n";
        open(FP, "< info.txt");

        while(<FP>){
                if(/location (\w+) age (\d+) phone (\d+)/){
        ($location,$age,$use) = ($1,$2,$3);

    print "$1 $2 $3\n";

    }

      if (/^$user\s*/){
        $hash->{$user}->{$location}->{location} = $location;
        $hash->{$user}->{$location}->{age} = $age;
        $hash->{$user}->{$location}->{phone} = $use;

       }

}

close(FP);

}

sub open_report{

 read_file();

 my $path = 0;

 for my $locationkey (sort keys %{$hash->{$user}}){
  _insertData($path,$locationkey);
  $path++;
  }

}


sub _insertData
{
    print "Inside insertdata\n";
    my $path = shift;
    my $location = shift;
    print "Inside insertdata $path | $location \n";
   
    $hl->add($path);
    $hl->itemCreate($path,0,-text=> $hash->{$user}->{$location}->{loca
+tion});
    $hl->itemCreate($path,1,-text=> $hash->{$user}->{$location}->{age}
+);
    $hl->itemCreate($path,2,-text=> $hash->{$user}->{$location}->{phon
+e});

}
[download]

Your logic problem is not quite so easy, and since you are not paying for this, I feel like it isn't my responsibility to sort out your logic, I prefer to let my mind rest on Saturday. :-) But, I will point out where and what your problem is. Here is the debug output I get after following your instructions about swapping in the new info.txt.

$$ ./1020153.pl
Inside read file 
usa 22 201
Inside insertdata
Inside insertdata 0 | usa 
Inside read file 
usa 22 201
clear_data usa
Inside refreshdata 0 | usa 
itemexists ...
Inside read file 
usa 22 201
clear_data usa
Inside refreshdata 0 | usa 
itemexists ...
Inside read file 
usa 22 201
germany 22 202
france 23 101
clear_data germany
Inside refreshdata 0 | germany 
itemexists ...
clear_data usa
Inside refreshdata 1 | usa 
XS_Tk__Callback_Call error:Entry "1" not found at /usr/lib/perl5/site_
+perl/5.14.1/x86_64-linux-thread-multi/Tk.pm line 251.

Tk::Error: Entry "1" not found at /usr/lib/perl5/site_perl/5.14.1/x86_
+64-linux-thread-multi/Tk.pm line 251.
 Tk callback for .frame1.frame.hlist
 Tk::After::repeat at /usr/lib/perl5/site_perl/5.14.1/x86_64-linux-thr
+ead-multi/Tk/After.pm line 80
 [repeat,[{},after#13,5000,repeat,[\&main::clear_data]]]
 ("after" script)
^C
[download]

As you can see if you closely look at it, when it starts it clears_data for usa fine, but after I switch in the full file, indicated by the lines

Inside read file 
usa 22 201
germany 22 202
france 23 101
clear_data germany
Inside refreshdata 0 | germany 
itemexists ...
clear_data usa
Inside refreshdata 1 | usa 
XS_Tk__Callback_Call error:Entry "1" not found at /usr/lib/perl5/site_
+perl/5.14.1/x86_64-linux-thread-multi/Tk.pm line 251.
[download]

After the full file is read, you clear_data for germany instead of usa, which what would be expected.

Like I said, it strains my mind to try to figure out someone else's spaghetti logic. Either I can spend all Saturday trying to debug that glitch, or you can, and guess what, I'm going to take a nap. :-)

If you really want to learn, you can run the code thru the ptkdb Tk debugger. There are many tutorials on ptkdb, just google for them. Good luck.