You aren't supplying enough information for anyone to really help you figure out your problem. The best I can come up with is "You're doing it wrong."

Try this code snippet to see if it gives you any pointers.

use strict;
use warnings;
use Tk;

my %w;

$w{mw} = MainWindow->new;

$w{topfr}  = $w{mw}->Frame()->pack( -expand => 1, -fill => 'x' );
$w{textfr} = $w{mw}->Frame()->pack( -expand => 1, -fill => 'both' );

$w{topfr}->Button(
    -text    => 'Previous',
    -command => sub { nextText('-backwards') }
)->pack( -side => 'left' );

$w{searchstring} =
  $w{topfr}->Entry( -text => 'text', )->pack( -side => 'left' );

$w{topfr}->Button(
    -text    => 'Next',
    -command => sub { nextText('-forwards') }
)->pack( -side => 'left' );

$w{textWindow} =
  $w{textfr}->Scrolled( 'Text', -scrollbars => 'ose' )
  ->pack( -expand => 1, -fill => 'both' );

$w{textWindow}->insert(
    'end',
q|I have a Scrolled Text widget in my application. I am trying to
implement an incremental search of a string on this text widget.
I have come up with the following logic , but it only highlights
the first occurence and not the remaining ocuurences. Please help
me to make it incremental for the entire text widget.
Following is my code |
);

$w{textWindow}->focus;
MainLoop;

sub nextText {
    my $direction = shift;
    my $string    = $w{searchstring}->get;
    $w{textWindow}->FindNext( $direction, '-exact', '-nocase', $string
+ );
}
[download]

Hi thundergnat
Despite insufficient information, you have understood my requirement excellently and exactly this is what I was looking for.
The only thing is "Previous" button working fine, but the "Next" button is only highlighting the first occurence of the search string and not able to go forward.
I checked with caller(0) and other print statements. While pressing "Next", it is getting called properly with proper argument i.e "-forwards" but still the problem persists.

Thanks anyways.

... The only thing is ... Thanks anyways.

Sorry , but prev/next both work in mr thundergnat's code

#!/usr/bin/perl --
use strict;
use warnings;

use Tk;

Main( @ARGV );
exit( 0 );

sub Main {
    tkgui(0, 'who appears selected ? (with exportselection only)');
    tkgui(1, 'who appears selected ? (with exportselection and callbac
+ks)');
}

sub tkgui {
    my ( $bind_callbacks , $message ) = @_;
    my $exportselection = 0;
    my $mw = MainWindow->new;
    my $filename = $message;
    
    my $f = $mw->Frame->pack( -side => 'top', -fill => 'x' );
    my $e = $f->Entry(
        -textvariable => \$filename,
        -exportselection => $exportselection,
    )->pack(
        -side   => 'left',
        -anchor => 'w',
        -fill   => 'x',
        -expand => 1,
    );

    my $t = $mw->Scrolled(
        "Text",
        -exportselection => $exportselection,
    )->pack(
        -side   => 'bottom',
        -fill   => 'both',
        -expand => 1,
    );

    $t->insert(
        end => join "\n",
            qw' to hilite highlight selection without w/o focus
                tagAdd tagname @range
                tagConfigure foreground and background
            ',
            1 .. 10,
    );

    if( $bind_callbacks  ){
        $t->bind( '<<Selection>>', \&on_selection );
        $t->bind( '<FocusOut>', sub { my ($t) = @_; }, );
    }

    $mw->withdraw;
    $mw->deiconify;
    $mw->raise;
    $mw->focusForce;
    $mw->update;
    
    for( 1 .. 5 ){
        $filename = "$message [I HAVE FOCUS]";
        $e->selectionRange(0, length($filename) - 8 );
        $e->focus ;
        $e->update;
        $mw->update;
        warn 'focusCurrent? ', eval { $mw->focusCurrent } || 'none';
        sleep 1;
        $filename = "$message [I LOST FOCUS]";
        $t->selectAll;
        $t->focus;
        $t->update;
        $mw->update;
        warn 'focusCurrent? ', eval { $mw->focusCurrent } || 'none';
        sleep 1;
    }
    $mw->withdraw;
    return $mw;
}


sub on_selection {
    my( $t ) = @_;
    $t->tagDelete('ssel');
    if ( my (@range) = $t->tagRanges('sel') ) {
        $t->tagAdd( ssel => @range );
        for my $opt (qw' foreground background ') {
            $t->tagConfigure( ssel => "-$opt" => $t->cget("select$opt"
+) );
        }
    }
    return;
}
[download]