sub IsNumber
{
   my ($string) = @_;

   $string =~s/ //g;
   my $valid = 0;
   my $count = $string =~ tr/\.//;

   if ( $string =~ m/[a-zA-Z\ \[\]]/ )
   {
      $valid = 0;
   }
   elsif ( $string =~ /[^\x00-\x7F]/ )
   {
      $valid = 0;
   }
   elsif ( $count > 1 )
   {
      $valid = 0;
   }
   elsif ( $string =~ m/[#@':;><,.{}[]=!"£$%^&*()]/ )
   {
      $valid = 0;
   }
   elsif ( $string =~ m/^[+-]?\d+$/ )
   {
      $valid = 1;
   }
   elsif ( $string =~ m/^[+-]?[0-9]+[.]?[0-9]+/ )
   {
      $valid = 1;
   }

   return $valid;
}