// Check browser version
var isNav4 = false, isNav5 = false, isIE4 = false
var strSeperator = "-";
// If you are using any Java validation on the back side you will want to use the / because
// Java date validations do not recognize the dash as a valid date separator.
var vDateType = 3; // Global value for type of date format
//                1 = mm/dd/yyyy
//                2 = yyyy/dd/mm  (Unable to do date check at this time)
//                3 = dd/mm/yyyy
var vYearType = 4; //Set to 2 or 4 for number of digits in the year for Netscape
var vYearLength = 2; // Set to 4 if you want to force the user to enter 4 digits for the year before validating.
var err = 0; // Set the error code to a default of zero
if(navigator.appName == "Netscape") {
if (navigator.appVersion < "5") {
isNav4 = true;
isNav5 = false;
}
else
if (navigator.appVersion > "4") {
isNav4 = false;
isNav5 = true;
   }
}
else {
isIE4 = true;
}
function DateFormat(vDateName, vDateValue, e, dateCheck, dateType) {
vDateType = dateType;
// vDateName = object name
// vDateValue = value in the field being checked
// e = event
// dateCheck
// True  = Verify that the vDateValue is a valid date
// False = Format values being entered into vDateValue only
// vDateType
// 1 = mm/dd/yyyy
// 2 = yyyy/mm/dd
// 3 = dd/mm/yyyy
//Enter a tilde sign for the first number and you can check the variable information.
if (vDateValue == "~") {
alert("AppVersion = "+navigator.appVersion+" \nNav. 4 Version = "+isNav4+" \nNav. 5 Version = "+isNav5+" \nIE Version = "+isIE4+" \nYear Type = "+vYearType+" \nDate Type = "+vDateType+" \nSeparator = "+strSeperator);
vDateName.value = "";
vDateName.focus();
return true;
}
var whichCode = (window.Event) ? e.which : e.keyCode;
// Check to see if a seperator is already present.
// bypass the date if a seperator is present and the length greater than 8
if (vDateValue.length > 8 && isNav4) {
if ((vDateValue.indexOf("-") >= 1) || (vDateValue.indexOf("/") >= 1))
return true;
}
//Eliminate all the ASCII codes that are not valid
var alphaCheck = " abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ/-";
if (alphaCheck.indexOf(vDateValue) >= 1) {
if (isNav4) {
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
}
else {
vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
return false;
   }
}
if (whichCode == 8) //Ignore the Netscape value for backspace. IE has no value
return false;
else {
//Create numeric string values for 0123456789/
//The codes provided include both keyboard and keypad values
var strCheck = '47,48,49,50,51,52,53,54,55,56,57,58,59,95,96,97,98,99,100,101,102,103,104,105';
if (strCheck.indexOf(whichCode) != -1) {
if (isNav4) {
if (((vDateValue.length < 6 && dateCheck) || (vDateValue.length == 7 && dateCheck)) && (vDateValue.length >=1)) {
alert("錯誤的日期\n請重新輸入");
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
}
if (vDateValue.length == 6 && dateCheck) {
var mDay = vDateName.value.substr(2,2);
var mMonth = vDateName.value.substr(0,2);
var mYear = vDateName.value.substr(4,4)
//Turn a two digit year into a 4 digit year
if (mYear.length == 2 && vYearType == 4) {
var mToday = new Date();
//If the year is greater than 30 years from now use 19, otherwise use 20
var checkYear = mToday.getFullYear() + 30;
var mCheckYear = '20' + mYear;
if (mCheckYear >= checkYear)
mYear = '19' + mYear;
else
mYear = '20' + mYear;
}
var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
if (!dateValid(vDateValueCheck)) {
alert("錯誤的日期\n請重新輸入");
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
}
return true;
}
else {
// Reformat the date for validation and set date type to a 1
if (vDateValue.length >= 8  && dateCheck) {
if (vDateType == 1) // mmddyyyy
{
var mDay = vDateName.value.substr(2,2);
var mMonth = vDateName.value.substr(0,2);
var mYear = vDateName.value.substr(4,4)
vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
}
if (vDateType == 2) // yyyymmdd
{
var mYear = vDateName.value.substr(0,4)
var mMonth = vDateName.value.substr(4,2);
var mDay = vDateName.value.substr(6,2);
vDateName.value = mYear+strSeperator+mMonth+strSeperator+mDay;
}
if (vDateType == 3) // ddmmyyyy
{
var mMonth = vDateName.value.substr(2,2);
var mDay = vDateName.value.substr(0,2);
var mYear = vDateName.value.substr(4,4)
vDateName.value = mDay+strSeperator+mMonth+strSeperator+mYear;
}
//Create a temporary variable for storing the DateType and change
//the DateType to a 1 for validation.
var vDateTypeTemp = vDateType;
vDateType = 1;
var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
if (!dateValid(vDateValueCheck)) {
alert("錯誤的日期\n請重新輸入");
vDateType = vDateTypeTemp;
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
}
vDateType = vDateTypeTemp;
return true;
}
else {
if (((vDateValue.length < 8 && dateCheck) || (vDateValue.length == 9 && dateCheck)) && (vDateValue.length >=1)) {
alert("錯誤的日期\n請重新輸入");
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
         }
      }
   }
}
else {
// Non isNav Check
if (((vDateValue.length < 8 && dateCheck) || (vDateValue.length == 9 && dateCheck)) && (vDateValue.length >=1)) {
alert("錯誤的日期\n請重新輸入");
vDateName.value = "";
vDateName.focus();
return true;
}
// Reformat date to format that can be validated. mm/dd/yyyy
if (vDateValue.length >= 8 && dateCheck) {
// Additional date formats can be entered here and parsed out to
// a valid date format that the validation routine will recognize.
if (vDateType == 1) // mm/dd/yyyy
{
var mMonth = vDateName.value.substr(0,2);
var mDay = vDateName.value.substr(3,2);
var mYear = vDateName.value.substr(6,4)
}
if (vDateType == 2) // yyyy/mm/dd
{
var mYear = vDateName.value.substr(0,4)
var mMonth = vDateName.value.substr(5,2);
var mDay = vDateName.value.substr(8,2);
}
if (vDateType == 3) // dd/mm/yyyy
{
var mDay = vDateName.value.substr(0,2);
var mMonth = vDateName.value.substr(3,2);
var mYear = vDateName.value.substr(6,4)
}
if (vYearLength == 4) {
if (mYear.length < 4) {
alert("錯誤的日期\n請重新輸入");
vDateName.value = "";
vDateName.focus();
return true;
   }
}
// Create temp. variable for storing the current vDateType
var vDateTypeTemp = vDateType;
// Change vDateType to a 1 for standard date format for validation
// Type will be changed back when validation is completed.
vDateType = 1;
// Store reformatted date to new variable for validation.
var vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
if (mYear.length == 2 && vYearType == 4 && dateCheck) {
//Turn a two digit year into a 4 digit year
var mToday = new Date();
//If the year is greater than 30 years from now use 19, otherwise use 20
var checkYear = mToday.getFullYear() + 30;
var mCheckYear = '20' + mYear;
if (mCheckYear >= checkYear)
mYear = '19' + mYear;
else
mYear = '20' + mYear;
vDateValueCheck = mMonth+strSeperator+mDay+strSeperator+mYear;
// Store the new value back to the field.  This function will
// not work with date type of 2 since the year is entered first.
if (vDateTypeTemp == 1) // mm/dd/yyyy
vDateName.value = mMonth+strSeperator+mDay+strSeperator+mYear;
if (vDateTypeTemp == 3) // dd/mm/yyyy
vDateName.value = mDay+strSeperator+mMonth+strSeperator+mYear;
}
if (!dateValid(vDateValueCheck)) {
alert("錯誤的日期\n請重新輸入");
vDateType = vDateTypeTemp;
vDateName.value = "";
vDateName.focus();
return true;
}
vDateType = vDateTypeTemp;
return true;
}
else {
if (vDateType == 1) {
if (vDateValue.length == 2) {
vDateName.value = vDateValue+strSeperator;
}
if (vDateValue.length == 5) {
vDateName.value = vDateValue+strSeperator;
   }
}
if (vDateType == 2) {
if (vDateValue.length == 4) {
vDateName.value = vDateValue+strSeperator;
}
if (vDateValue.length == 7) {
vDateName.value = vDateValue+strSeperator;
   }
}
if (vDateType == 3) {
if (vDateValue.length == 2) {
vDateName.value = vDateValue+strSeperator;
}
if (vDateValue.length == 5) {
vDateName.value = vDateValue+strSeperator;
   }
}
return true;
   }
}
if (vDateValue.length == 10&& dateCheck) {
if (!dateValid(vDateName)) {
// Un-comment the next line of code for debugging the dateValid() function error messages
//alert(err);
alert("錯誤的日期\n請重新輸入");
vDateName.focus();
vDateName.select();
   }
}
return false;
}
else {
// If the value is not in the string return the string minus the last
// key entered.
if (isNav4) {
vDateName.value = "";
vDateName.focus();
vDateName.select();
return false;
}
else
{
vDateName.value = vDateName.value.substr(0, (vDateValue.length-1));
return false;
         }
      }
   }
}
function dateValid(objName) {
var strDate;
var strDateArray;
var strDay;
var strMonth;
var strYear;
var intday;
var intMonth;
var intYear;
var booFound = false;
var datefield = objName;
var strSeparatorArray = new Array("-"," ","/",".");
var intElementNr;
// var err = 0;
var strMonthArray = new Array(12);
strMonthArray[0] = "Jan";
strMonthArray[1] = "Feb";
strMonthArray[2] = "Mar";
strMonthArray[3] = "Apr";
strMonthArray[4] = "May";
strMonthArray[5] = "Jun";
strMonthArray[6] = "Jul";
strMonthArray[7] = "Aug";
strMonthArray[8] = "Sep";
strMonthArray[9] = "Oct";
strMonthArray[10] = "Nov";
strMonthArray[11] = "Dec";
//strDate = datefield.value;
strDate = objName;
if (strDate.length < 1) {
return true;
}
for (intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) {
if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
strDateArray = strDate.split(strSeparatorArray[intElementNr]);
if (strDateArray.length != 3) {
err = 1;
return false;
}
else {
strDay = strDateArray[0];
strMonth = strDateArray[1];
strYear = strDateArray[2];
}
booFound = true;
   }
}
if (booFound == false) {
if (strDate.length>5) {
strDay = strDate.substr(0, 2);
strMonth = strDate.substr(2, 2);
strYear = strDate.substr(4);
   }
}
//Adjustment for short years entered
if (strYear.length == 2) {
strYear = '20' + strYear;
}
strTemp = strDay;
strDay = strMonth;
strMonth = strTemp;
intday = parseInt(strDay, 10);
if (isNaN(intday)) {
err = 2;
return false;
}
intMonth = parseInt(strMonth, 10);
if (isNaN(intMonth)) {
for (i = 0;i<12;i++) {
if (strMonth.toUpperCase() == strMonthArray[i].toUpperCase()) {
intMonth = i+1;
strMonth = strMonthArray[i];
i = 12;
   }
}
if (isNaN(intMonth)) {
err = 3;
return false;
   }
}
intYear = parseInt(strYear, 10);
if (isNaN(intYear)) {
err = 4;
return false;
}
if (intMonth>12 || intMonth<1) {
err = 5;
return false;
}
if ((intMonth == 1 || intMonth == 3 || intMonth == 5 || intMonth == 7 || intMonth == 8 || intMonth == 10 || intMonth == 12) && (intday > 31 || intday < 1)) {
err = 6;
return false;
}
if ((intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11) && (intday > 30 || intday < 1)) {
err = 7;
return false;
}
if (intMonth == 2) {
if (intday < 1) {
err = 8;
return false;
}
if (LeapYear(intYear) == true) {
if (intday > 29) {
err = 9;
return false;
   }
}
else {
if (intday > 28) {
err = 10;
return false;
      }
   }
}
return true;
}
function LeapYear(intYear) {
if (intYear % 100 == 0) {
if (intYear % 400 == 0) { return true; }
}
else {
if ((intYear % 4) == 0) { return true; }
}
return false;
}