function IsAlphabetic(sText)
{
   var ValidChars = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ.,";
   var IsAlpha = true;
   var Char;

   for (i = 0; i < sText.length && IsAlpha == true; i++)
   {
      Char = sText.charAt(i);
      if (ValidChars.indexOf(Char) == -1)
      {
         IsAlpha = false;
      }
   }
   return IsAlpha;
}