sub kill_process{
   do
    {
     print"Kill processes for the user (y orn?\n";
     my $ans = <>;
     chomp $ans;
     print "choose pid: "\n;
     my $pid =<>;
     chomp $pid;
     system `kill $pid`;
     print "process killed \n";
     }while ($ans eq "Y" || $ans eq "y");
},