// JavaScript Document

function checkEmail(email) {
	var filter = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	if (!filter.test(email)) {
		return false;
	}
	else {
		return true;
	}
}

function isEmail(str) {
  // are regular expressions supported?
  var supported = 0;
  if (window.RegExp) {
	var tempStr = "a";
	var tempReg = new RegExp(tempStr);
	if (tempReg.test(tempStr)) supported = 1;
  }
  if (!supported) 
	return (str.indexOf(".") > 2) && (str.indexOf("@") > 0);
  var r1 = new RegExp("(@.*@)|(\\.\\.)|(@\\.)|(^\\.)");
  var r2 = new RegExp("^.+\\@(\\[?)[a-zA-Z0-9\\-\\.]+\\.([a-zA-Z]{1,5}|[0-9]{1,5})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}