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

function IsValidFromAddress(sText)
{
	if( sText.charAt(0)=='+' )
	{
		// this should be a phone number
		sText = sText.substring(1,sText.length-1);
		if( sText.length>16 )
		{
			return false;
		}
		return IsValidPhoneNumber(sText,false);
	}	
	else if( sText.lengh>11 )
	{
		return false;
	}
	return true;
}

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