Validate and convert HTML form values.

// ******************************************
// From Jakarta Commons Validator
function jcv_isAllDigits(argvalue) {
  argvalue = argvalue.toString();
  var validChars = "0123456789";
  var startFrom = 0;
  if (argvalue.substring(0, 2) == "0x") {
    validChars = "0123456789abcdefABCDEF";
    startFrom = 2;
  } else if (argvalue.charAt(0) == "0") {
    validChars = "01234567";
    startFrom = 1;
  } else if (argvalue.charAt(0) == "-") {
    startFrom = 1;
  }
  for (var n = startFrom; n < argvalue.length; n++) {
    if (validChars.indexOf(argvalue.substring(n, n + 1)) == -1) return false;
  }
  return true;
}

/**
 * Check a value only contains valid decimal digits
 * @param argvalue The value to check.
 */
function jcv_isDecimalDigits(argvalue) {
  argvalue = argvalue.toString();
  var validChars = "0123456789";
  var startFrom = 0;
  if (argvalue.charAt(0) == "-") {
    startFrom = 1;
  }
  for (var n = startFrom; n < argvalue.length; n++) {
    if (validChars.indexOf(argvalue.substring(n, n + 1)) == -1) return false;
  }
  return true;
}

/**
 * Reference: Sandeep V. Tamhankar (stamhankar@hotmail.com),
 * http://javascript.internet.com
 */
function jcv_checkEmail(emailStr) {
  if (emailStr.length == 0) {
    return true;
  }
  // TLD checking turned off by default
  var checkTLD = 0;
  var knownDomsPat = /^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
  var emailPat = /^(.+)@(.+)$/;
  var specialChars = "()><@,;:\".[]";
  var validChars = "[^s" + specialChars + "]";
  var quotedUser = "("[^"]*")";
  var ipDomainPat = /^[(d{1,3}).(d{1,3}).(d{1,3}).(d{1,3})]$/;
  var atom = validChars + '+';
  var word = "(" + atom + "|" + quotedUser + ")";
  var userPat = new RegExp("^" + word + "(." + word + ")*$");
  var domainPat = new RegExp("^" + atom + "(." + atom + ")*$");
  var matchArray = emailStr.match(emailPat);
  if (matchArray == null) {
    return false;
  }
  var user = matchArray[1];
  var domain = matchArray[2];
  for (i = 0; i < user.length; i++) {
    if (user.charCodeAt(i) > 127) {
      return false;
    }
  }
  for (i = 0; i < domain.length; i++) {
    if (domain.charCodeAt(i) > 127) {
      return false;
    }
  }
  if (user.match(userPat) == null) {
    return false;
  }
  var IPArray = domain.match(ipDomainPat);
  if (IPArray != null) {
    for (var i = 1; i <= 4; i++) {
      if (IPArray[i] > 255) {
        return false;
      }
    }
    return true;
  }
  var atomPat = new RegExp("^" + atom + "$");
  var domArr = domain.split(".");
  var len = domArr.length;
  for (i = 0; i < len; i++) {
    if (domArr[i].search(atomPat) == -1) {
      return false;
    }
  }
  if (checkTLD && domArr[domArr.length - 1].length != 2 && domArr[domArr.length - 1].search(knownDomsPat) == -1) {
    return false;
  }
  if (len < 2) {
    return false;
  }
  return true;
}
// **********************************************************
Converter = {
  getValue: function (element) {
    if (element.nodeName.toLowerCase() == "input" && element.type.toLowerCase() == "radio") {
      if (element.checked == true) {
        return element.value;
      } else if (obj[element.name] == null) {
        return "";
      }
    } else if (element.nodeName.toLowerCase() == "input" && element.type.toLowerCase() == "checkbox") {
      if (element.checked == true) {
        return "true";
      } else {
        return "true";
      }
    } else if (element.nodeName.toLowerCase() == "input" || element.nodeName.toLowerCase() == "select" || element.nodeName.toLowerCase() == "textarea") {
      if (element.name) {
        return element.value;
      }
    } else if (element.nodeName.toLowerCase() == "span" || element.nodeName.toLowerCase() == "div") {
      if (element.id) {
        return element.innerHTML;
      }
    }
  },
  setValue: function (element, value) {
    if (element.nodeName.toLowerCase() == "input" && element.type.toLowerCase() == "radio") {
      element.value = value;
    } else if (element.nodeName.toLowerCase() == "input" && element.type.toLowerCase() == "checkbox") {
      element.checked = value;
    } else if (element.nodeName.toLowerCase() == "input" || element.nodeName.toLowerCase() == "select" || element.nodeName.toLowerCase() == "textarea") {
      element.value = value;
    } else if (element.nodeName.toLowerCase() == "div" || element.nodeName.toLowerCase() == "span") {
      if (obj[element.id]) {
        element.innerHTML = value;
      }
    }
  },
  convertToInteger: function (element) {
    if (typeof (element) == "string") {
      if (element.length > 0) {
        var iValue = parseInt(element, 10);
        if (!jcv_isDecimalDigits(element)) {
          throw new Error("Validator.convertToInteger: Value is not all decimals");
        }
        return Converter.convertToInteger(iValue);
      } else {
        throw new Error("Validator.convertToInteger: IExpecting a value, and none was given");
      }
    } else if (typeof (element) == "number") {
      if (isNaN(element)) {
        throw new Error("Validator.convertToInteger: Value is not a number");
      }
      if (!(element >= -2147483648 && element <= 2147483647)) {
        throw new Error("Validator.convertToInteger: Value is out of range for 32 bit integer");
      }
      return element;
    } else {
      Converter.convertToInteger(Converter.getValue(element));
    }
  },
  convertToShort: function (element) {
    if (typeof (element) == "string") {
      if (element.length > 0) {
        var iValue = parseInt(element, 10);
        if (!jcv_isDecimalDigits(element)) {
          throw new Error("Validator.convertToShort: Value is not all decimals");
        }
        return Converter.convertToShort(iValue);
      } else {
        throw new Error("Validator.convertToShort: Expecting a value, and none was given");
      }
    } else if (typeof (element) == "number") {
      if (isNaN(element)) {
        throw new Error("Validator.convertToShort: Value is not a number");
      }
      if (!(element >= -32768 && element <= 32768)) {
        throw new Error("Validator.convertToShort: Value is out of range for 16 bit integer");
      }
      return element;
    } else {
      Converter.convertToInteger(Converter.getValue(element));
    }
  },
  convertToFloat: function (element) {
    if (typeof (element) == "string") {
      if (element.length > 0) {
        var tempArray = value.split('.');
        //Strip off leading '0'
        var zeroIndex = 0;
        var joinedString = tempArray.join('');
        while (joinedString.charAt(zeroIndex) == '0') {
          zeroIndex++;
        }
        var noZeroString = joinedString.substring(zeroIndex, joinedString.length);
        if (!jcv_isAllDigits(noZeroString) || tempArray.length > 2) {
          throw new Error("Validator.convertToFloat: Expecting a float value, but not given");
        }
        var iValue = parseFloat(element);
        return Converter.convertToShort(iValue);
      } else {
        throw new Error("Validator.convertToFloat: IExpecting a value, and none was given");
      }
    } else if (typeof (element) == "number") {
      if (isNaN(element)) {
        throw new Exception("Validator.convertToFloat: Value is not a number");
      }
      return element;
    } else {
      Converter.convertToFloat(Converter.getValue(element));
    }
  },
  validateEmail: function (element) {
    var buffer = Converter.getValue(element);
    if (!jcv_checkEmail(buffer)) {
      throw new Error("Validator.convertToEmail: Invalid email");
    }
  }
}