// general purpose function to see if an input value has been
// entered at all
function isEmpty(inputStr) {
  if (inputStr == null || inputStr == "") {
    return true;
  }
  return false;
}

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]{2,3}|[0-9]{1,3})(\\]?)$");
  return (!r1.test(str) && r2.test(str));
}