function ltrim(sString) 
{
  var c;
  while((c=sString.substring(0,1)) == ' ' || c == '\r' || c == '\n' || c == '\t')
  {
    sString = sString.substring(1, sString.length);
  }
  return sString;
}

function rtrim(sString) 
{
  var c;
  while ((c=sString.substring(sString.length-1, sString.length)) == ' ' || c == '\r' || c == '\n' || c == '\t')
  {
    sString = sString.substring(0,sString.length-1);
  }
  return sString;
}
  
function trim(sString)
{
  sString = ltrim(sString);
  sString = rtrim(sString);
  return sString;
}

function IsNumeric(sText)
{
   var ValidChars = "-+0123456789.";
   var IsNumber = true;
   var Char;
 
   for(var i = 0; i < sText.length && IsNumber === true; i++) 
   {
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
      {
         IsNumber = false;
      }
   }
   
   return IsNumber;
}