/*
Description:	Common function used by all form object and possibly other library class
Author:			Tim Chan
Version:		1.0
Date:			5 May 2004
Specification:	Javascript v1.2
Feature:		First version.
				Check for the regular expression in the string.
				Check for blank value in the string.
				Check for decimal value in the string.
				Check for integer value in the string.
				Check for positive (decimal) number in the string.
				Check for email address.
				Check for postcode (Australia)
*/
function Expression(){
  return Expression;
}

Expression.isExpression = function(s, expr) {
	var pattern = new RegExp(expr);
    return pattern.test(s);
}

Expression.isBlank = function(s) {
  return s == "" || Expression.isExpression(s, "^\\s+$");
}
  
Expression.isDecimal = function(s) {
  if (((parseFloat(s) / parseFloat(s) ) != 1) && (parseFloat(s) != 0))
    return false;
  else
    return true;
}

Expression.isInteger = function(s) {
  return Expression.isExpression(s, "^\\d+$");
}
  
Expression.isPositive = function(s) {
  return parseFloat(s) >= 0;
}
  
Expression.isEmail = function(s) {
  return Expression.isExpression(s, "^.+\\@.+\\..+$");
}
  
Expression.isPostcode = function(s) {
  return Expression.isExpression(s, "^\\d{4}$");
}