function decryptContact( string )
{
  var aCode = 'a'.charCodeAt();
  var zCode = 'z'.charCodeAt();
  var ACode = 'A'.charCodeAt();
  var ZCode = 'Z'.charCodeAt();
  
  var result = '';
  
  for (var c = 0; c < string.length; c++) 
  {
    var charCode = string.charCodeAt(c);
    
    if ( charCode >= aCode && charCode <= zCode )
      charCode = aCode + (charCode - aCode + 13) % 26;
    else if ( charCode >= ACode && charCode <= ZCode )
      charCode = ACode + (charCode - ACode + 13) % 26;
    
    result += String.fromCharCode(charCode);
  }
  
  return result;
}