function Trim(s)
{
  if (s==null) return null;
  var r = s;
  while (r.length>0 && (r.charAt(0)==' '||r.charAt(0)=='\r'||r.charAt(0)=='\n'||r.charAt(0)=='\t')) {
    r = r.substring(1, r.length);
  }
  while (r.length>0 && (r.charAt(r.length-1)==' '||r.charAt(r.length-1)=='\r'||r.charAt(r.length-1)=='\n'||r.charAt(r.length-1)=='\t')) {
    r = r.substring(0, r.length-1);
  }
  return r;
}