Its a quite big program and i thought it'll mess up the forum. Anyways i'll post the entire program now.

my $i=1;
my $array_var;
my $window = MainWindow->new;
$window->title("Breadcrumb Buster");
$window->geometry("600x850");
#my $window=$window->Frame()->pack();
my $lbl_var_1 = $window -> Label(-text=>"Enter the keyword: ")->pack()
+;
my $txt_var_1 = $window -> Entry()->pack(-pady=>20);
my $btn_var_1 = $window -> Button(-text => "Get Breadcrumb !", -comman
+d => \&Getbread)->pack();

$array_var->{"0,0"} = "Sno";
$array_var->{"0,1"} = "Manufacturer Name";
$array_var->{"0,2"} = "Manufacturer URL";
$array_var->{"0,3"} = "Breadcrumb";
my $table = $window->Scrolled('TableMatrix', -cols=>4, -drawmode=>'fas
+t', -variable => $array_var,-state=>"disabled", -flashtime=>0.25,-fla
+shmode=>1,-resizeborders => 'both',-colstretchmode => 'unset', -rowst
+retchmode => 'last')->pack(-pady=>20, -fill=>'x');
$table->configure(-height=>"200");
#$table->rowHeight(0,1);
$table->tagRow('title',0);
$table->tagConfigure('title', -bd=>2, -relief=>'raised');
$table->tagConfigure('OddRow', -bg => 'white', -fg => 'purple');
#$table->colWidth(0,5,3,6,4,10);

sub Getbread()
{
    my $bread;
    my $input_keyword=$txt_var_1->get();
    print "$input_keyword\n";
    my $query_url="http://www.google.com/products?as_q=$input_keyword&
+as_epq=&as_oq=&as_eq=&num=100&scoring=r&as_occt=any&price1=&price2=&s
+how=dd&safe=active";
    loop:
    my $content=&Geturl($query_url);
    while($content=~m/<li\s*class\=\"result\"[^>]*?>([\w\W]*?)<\/li>/i
+gs)
    {
        my ($temp_content, $cse_url, $cse_url_temp, $cse_url_old, $pro
+duct_title, $new_price, $used_price, $number_sellers, $cse_content, $
+mer_url, $merchant_name);
        $temp_content=$1;
        if($temp_content=~m/\"result\-seller\">\s*from\s*[\d]+\s*selle
+rs/is)
        {
            if($temp_content=~m/<h3\s*class\=\"result\-title\">\s*<a\s
+*href\=\"([^>]*?)\"\s*>\s*([\w\W]*?)\s*<\/h3>/is)
            {            
                $cse_url_temp=$1;
                $product_title=$2;
                $cse_url="http://www.google.com".$cse_url_temp;
                decode_entities($cse_url);
                $product_title=~s/<[^>]*?>//igs;
                decode_entities($product_title);
                $product_title=~s/\'/\'\'/igs;
            }
            $cse_url=~s/\#p/\&os\=sellers\#p/igs;
            $cse_url_old=$cse_url;
            paging:
            $cse_content=&Geturl($cse_url);
            while($cse_content=~m/(<tr[^>]*?id\=\"[^>]*?>[\w\W]*?<\/sp
+an>\s*<\/td>\s*<\/tr>)/igs)
            {
                my ($yahoo_store, $meta_keyword, $meta_description, $m
+erchant_content, $online_since, $alexa_rank, $merchant_status,  $merc
+hant_url_temp, $merchant_url, $merchant_name, $temp_cse_content);
                $temp_cse_content=$1;
                if($temp_cse_content=~m/\"seller\-name\"><a\s*href\=\"
+[^>]*?\?q\=(http(?:s)?\:\/\/[^>]*?\/[^>]*?)\&fr[^>]*?\"\s*>([\w\W]*?)
+<\/a>/is)
                {
                    $mer_url=$1;
                    $merchant_name=$2;
                    $merchant_name=decode_entities($merchant_name);
                    $merchant_name=~s/\'/\'\'/igs;
                    $mer_url=uri_unescape($mer_url);                  
+  
                }
                $bread=&Get_merchant($mer_url);
                
            }
        }
        elsif($temp_content=~m/<h3\s*class\=\"result\-title\">\s*<a\s*
+href\=\"([^>]*?)\"\s*>\s*([\w\W]*?)\s*<\/h3>/is)
        {
            $cse_url_temp=$1;
            $cse_url_temp=uri_unescape($cse_url_temp);
            $merchant_name=$2;
            if($cse_url_temp=~m/q\=([^>]*?)\&fr/is)
            {
                $mer_url=$1;
                $mer_url=uri_unescape($mer_url);
            }
            $merchant_name=~s/<[^>]*?>/ /igs;
            $bread=&Get_merchant($mer_url);    
                
        }
        if($bread ne "")
        {
            $array_var->{"$i,0"} = $i ;
            $array_var->{"$i,1"} = "$merchant_name";
            $array_var->{"$i,2"} = "$mer_url";
            $array_var->{"$i,3"} = "$bread";            
            $i++;
            print "\n$merchant_name";
            last if $i==6;
        }        
    }
}

sub Geturl()
{
    my $url=shift;
    $url=uri_unescape(uri_unescape(uri_unescape($url)));
    start:
     my $req=HTTP::Request->new(GET => "$url");
    $req->header("Content-Type"=> "application/x-www-form-urlencoded")
+;
    my $res=$ua->request($req);
    my $con=$res->content(); 
    
    if($con=~m/<form\s*action\=\"Captcha\"/is)
    {
        print "\nGoogle Blocked - Now Sleeping...";
        sleep(1200);
        goto start;
    }
    return $con;
}

sub Get_merchant()
{
    my $merchant_url=shift;
    my $breadcrumb;
    my $merchant_content=&Geturl($merchant_url);
    if($merchant_content=~m/<h1\s*class\=\"breadcrumbfull\">\s*([\w\W]
+*?)\s*<\/h1>/is)
    {
        $breadcrumb=$1;
    }
    elsif($merchant_content=~m/<div[^>]*?(?:bread|crumb)[^>]*?>\s*([\w
+\W]*?)\s*<\/div>/is)
    {
        $breadcrumb=$1;
    }    
    elsif($merchant_content=~m/<td[^>]*?NavPath[^>]*?>\s*([\w\W]*?)\s*
+<\/td>/is)
    {
        $breadcrumb=$1;
    }
    $breadcrumb=~s/<[^>]*?>//igs;
    decode_entities($breadcrumb);
    $breadcrumb=~s/\'/\'\'/igs;
    chomp($breadcrumb);
    return $breadcrumb;    
}

MainLoop;
[download]

Your problem is a common one, in all gui toolkits, it's called "blocking the event loop". All gui's use an event loop, that is why they can be responsive to button clicks, etc. When you put a sleep statement, or do something which is long and intensive like getting a url thru a slow netlink, the event loop will freeze until it regains control. This can be shown is the following example. After 2.5 seconds, it will freeze for 5 seconds

#!/usr/bin/perl
use Tk;

my $mw = MainWindow->new;
$mw->geometry('100x100+100+100');
#$mw->overrideredirect(1);

my @color = qw/red green/;

my $bits = pack("b8"x8,
"...11...",
"..1111..",
".111111.",
"11111111",
"11111111",
".111111.",
"..1111..",
"...11...",);

$mw->DefineBitmap('indicator' => 8,8, $bits);

my $label = $mw->Label(
              -bitmap=>'indicator', 
          -bg=>'black',
          -fg=>'red',
          )->pack;

$mw->repeat(500,sub{$label->configure(
                               -fg=>$color[0]);
                               @color=reverse(@color);
 });


# put in simulated eventloop blocker after 2.5 seconds
# to freeze tk for 5 seconds
$mw->after(2500,sub{ sleep (5)  });

MainLoop;
[download]

There are many ways around this problem. First never use sleep in a gui app, unless it's in a thread. Second, put your url_fetching operations into threads or fork them off. You can try to manually pump the loop by liberally sprinkingly DoOneEvent(); in areas where the code is in a delay loop( like your in while( $fh ). Finally, use Tk::fileevent to read your filehandles, instead of a while loop. Use timers when needing delays, like Tk::repeat.

There are many examples out there on google for using Tk with threads and shared variables. See Tk events by Lidie and a few examples of using threads and fileno's with Tk ztk-BBC-World-News-Rss-TickerTape and Re^3: Passing globs between threads

---

I'm not really a human, but I play one on earth.
Old Perl Programmer Haiku

As an alternative to using threads, it is also possible to unblock the event loop by manually calling $mw->update() at frequent intervals to alllow the GUI to update, respond etc. This may or may not be easier/better for you, depending on what you are trying to do. I think it doesn't matter what Tk object you call the update() method on, although I usually use the main window.

--

"Any sufficiently analyzed magic is indistinguishable from science" - Agatha Heterodyne

always i love your code zentara ; it is lucid and educational
thanks