PowerShell v2 Function ConvertFrom Rot13

Here is a quick function to convert ROT13 values (check them out here if you dont know what it is) for PowerShell. No encoding, purely decoding:

function ConvertFrom-Rot13

{

     [CmdletBinding()]

     param(

          [Parameter(

              Mandatory = $true,

              ValueFromPipeline = $true

          )]

          [String]

          $rot13string

     )

    

     [String] $string = $null;

     $rot13string.ToCharArray() |

     ForEach-Object{

          Write-Verbose"$($_): $([int] $_)"

          if((([int] $_ -ge 97) -and ([int] $_ -le 109)) -or (([int] $_ -ge 65) -and ([int] $_ -le 77)))

          {

              $string += [char] ([int] $_ + 13);

          }

          elseif((([int] $_ -ge 110) -and ([int] $_ -le 122)) -or (([int] $_ -ge 78) -and ([int] $_ -le 90)))

          {

              $string += [char] ([int] $_ - 13);

          }

          else

          {

              $string += $_

          }

     }

     $string

}