下面的IsDateValid函数以美国格式验证日期。我将更改为将其转换为以欧洲格式验证日期。当验证工作时，用户可以通过简单地输入+或 - 符号来输入日期，具体取决于他们想要的内容，即过去的日期或未来的日期。
function IsLeapYear(year) {
//Convert from string to number
year = year - 0;
if ((year/4) != Math.floor(year/4)) return false;
if ((year/100) != Math.floor(year/100)) return true;
if ((year/400) != Math.floor(year/400)) return false;
return true;
} //function IsLeapYear...
function countChar(str, daChar) {
//See how many of 'dachar' are in 'str' and return as daCount
var daCount=0;
for (i = 0; i < str.length; i++) {
if (str.charAt(i) == daChar)
//increment count each time we find daChar in str
daCount++;
}
return daCount;
} //function countChar...
function IsDateValid(dateField, noDateRqrd) {
//If no date is required and they didn't enter one, then go back
if (((typeof noDateRqrd != "undefined") && (dateField.value.length == 0))||dateField.value.length == 0)
return null;
//We're going to check this date so go on
var GoodLength = false;
var msg='';
var daysOfMonth = new Array(31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
var daysOfMonthLY = new Array(31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31);
//Make sure they have the right number of '/'
var cCount=countChar(dateField.value,'/');
//force a date value
if (dateField.value.length >= 3) {
//alert('cc: ' + cCount + 'fl: ' + dateField.value.length);
if ((cCount == 1) && (dateField.value.length >= 3) && (dateField.value.length <= 5))
GoodLength=true;
else if ((cCount == 2) && (dateField.value.length >= 4) && (dateField.value.length <= 10))
GoodLength=true;
}
//If the length is good, then let's check the contents of the dateField
if (GoodLength == true) {
var firstslash=dateField.value.indexOf('/')+1; //must add 1 to get real position
var lastslash=dateField.value.lastIndexOf('/')+1;
/****************************
Note: substr is not included in CFStudio so 'substr' will not be bolded & blue
*****************************/
var month=dateField.value.substr(0,firstslash-1);
if ((!isNaN(month)) && (month < 13)){
if (firstslash != lastslash) {
//alert(dateField.value);
var day=dateField.value.substr(firstslash,lastslash-firstslash-1); //lastslash-firstslash+1
//We only need to tell it where to cut off the first char
var year=dateField.value.substr(lastslash);
//Access dates can range from 100 to 9999.
//SQL Server dates can range from 1753 to 9999.
//Since this code can run for either db, we'll use the more restrivtive date of 1753.
//The length test will catch any date > 9999.
if (!isNaN(day)&&!isNaN(year)&&(year.length < 5)){
//If there isn't a year value, then put in the current year
if (year.length == 0) {
//There is no year so we only need to get day
var day=dateField.value.substr(firstslash,lastslash-firstslash-1);
//Since they didn't enter a year, we'll use the current year
var now = new Date();
year=now.getFullYear();
dateField.value = month + "/" + day + "/" + year;
} else if ((year.length == 1) || (year.length == 2)) {
var tmpDate = new Date(dateField.value);
//Programmer's Note: entered value of "00" would be return as "1900" by getFullYear
tmpDate_yyyy = tmpDate.getFullYear()-1900; //Get 4 dig date and reindex without centuary
//alert('tmpDate_yyyy: ' + tmpDate_yyyy);
if (tmpDate_yyyy < 100) { //If less than 100, then we're in 20th centuary
if (tmpDate_yyyy < 60) //do 00 to 59 as 20xx
tmpDate.setFullYear(2000 + tmpDate_yyyy); //reset year to 21st centuary
else //do 60 to 99 as 19xx
tmpDate.setFullYear(1900 + tmpDate_yyyy); //reset year to 20th centuary
//Have to do it the hard way or we'll also get day, time, etc. which we don't want here
//getMonth is zero based so it returns a number one less that we want
}
dateField.value = tmpDate.getMonth()+1 + "/" + tmpDate.getDate() + "/" + tmpDate.getFullYear();
} else if ((year.length == 4)&&(year > 1752)) {
dateField.value = day + "/" + Month + "/" + year;
} else {
msg= 'The date you entered is not valid: ' + dateField.value + '.';
}//if
} else {
msg= 'The date you entered is not valid: ' + dateField.value + '.';
} //if
} else {
//There is no year so we only need to get day
var day=dateField.value.substr(firstslash);
if (!isNaN(day)) {
//Since they didn't enter a year, we'll use the current year
var now = new Date();
var year=now.getFullYear();
dateField.value = month + "/" + day + "/" + year;
} else {
msg= 'The day you entered is not valid: ' + dateField.value + '.';
} //if
}
//alert('m: ' + month + ' d: ' + day + ' y:' + year);
if ((day==0)||(IsLeapYear(year) && day > daysOfMonthLY[month-1])||(!IsLeapYear(year) && day > daysOfMonth[month-1]))
msg= 'The date you entered is not valid: ' + dateField.value + '.';
} else {
msg='The month you entered is not valid: ' + month + '.';
}
} else {
if (dateField.value.length == 0) {
msg= 'You must enter enter a valid Date.';
} else if ((dateField.value.toLowerCase() == 'today')||(dateField.value.toLowerCase() == 'now')) {
var now = new Date();
var day=now.getDate();
var month=now.getMonth()+1; //Have to add 1 to get correct month
var year=now.getFullYear();
dateField.value = month + "/" + day + "/" + year;
} else if ((dateField.value.indexOf('+') == 0)||(dateField.value.indexOf('-') == 0)) {
//alert('in: ' + dateField.value + ', NaN: ' + isNaN(dateField.value));
if (!isNaN(dateField.value)) {
var now = new Date();
var nowMS = now.getTime(); //Get the current time in milliseconds
//Add the number of milliseconds in a day times the number of days requested
//Use the Math.floor to make sure we only get whole days in case they add a decimal value
now.setTime(nowMS + Math.floor((dateField.value * 1000*60*60*24)));
var day=now.getDate();
var month=now.getMonth()+1; //Have to add 1 to get correct month
var year=now.getFullYear();
dateField.value = month + "/" + day + "/" + year;
} else
msg= 'The proper format, +#, or -#, with no spaces in between: e.g., "+6", or "-2". You entered: "' + dateField.value + '".';
} else
msg= '146: The date you entered is not valid: "' + dateField.value + '".';
}
if(msg.length > 0) {
if (typeof noDateRqrd == 'undefined') {
var lastLine="Select 'OK' to re-enter value, or 'Cancel' to enter the current date.\n\n"
} else {
var lastLine="Select 'OK' to re-enter value, or 'Cancel' to clear the date.\n\n"
}
var conmsg ="\n\n____________________________________________________\n\n" +
msg +
"\n\n____________________________________________________\n\n" +
"A valid date must contain at least one forward slash '/' as well as a day and a month.\n" +
"If you leave the year blank, then the current year will be inserted.\n\n" +
"The allowable date range is from 1/1/1753 to 12/31/9999.\n\n" +
lastLine
if (confirm(conmsg))
dateField.focus();
else {
if (typeof noDateRqrd == 'undefined') {
//get the current time
var Now=new Date();
dateField.value=Now.getMonth()+1 + "/" + Now.getDate() + "/" + Now.getFullYear();
} else {
dateField.value="";
}
}
return false;
} else
return true;
} //function IsDateValid