// DATE VALIDATION AND CONVERSION ROUTINE
// Automatically validates dates and converts to dd mmm yyyy format
// USAGE:
// To validate and convert dates upon field.lostfocus
//
// To verify that one date field is later than the other
//
// (Substitute field references as appropriate)
// PLACE FOCUS ON FIRST ENTRY FIELD
// Sets focus to the first form field on a page.
// USAGE:
// Include in body tag -
function checkdate(objName) {
if (!chkdate(objName)) {
objName.select();
alert("That date is invalid. Please try again.");
objName.focus();
return false;
} else {
return true;
}
}
function chkdate(objName) {
//var strDatestyle = "US"; // United States date style (month, day, year)
var strDatestyle = "EU"; // European date style (day, month, year)
var strMonthArray = new Array("Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec");
var strDate = objName.value;
// A blank field is a valid date, as far as we're concerned
if (strDate.length < 1)
return true;
var strDateParts = splitDateParts(strDate);
if (!strDateParts)
return false;
var strDay = strDateParts[0];
var strMonth = strDateParts[1];
var strYear = strDateParts[2];
// If we're doing US style, the month was first, so swap the values
if (strDatestyle == "US") {
strDay = strDateParts[1];
strMonth = strDateParts[0];
}
// We learnt our lesson from Y2k :)
if (strYear.length == 2)
strYear = (parseInt(strYear) < 30 ? '20' : '19') + strYear;
// Get the numeric day
var intDay = parseInt(strDay, 10);
if (isNaN(intDay))
return false;
// Try for a numeric month
var intMonth = parseInt(strMonth, 10);
// If the month isn't numeric, maybe it's a name?
if (isNaN(intMonth)) {
for (var i = 0; i < 12; i++) {
if (strMonth.substr(0, 3).toUpperCase() == strMonthArray[i].toUpperCase()) {
intMonth = i + 1;
strMonth = strMonthArray[i];
break;
}
}
if (isNaN(intMonth))
return false;
}
// Is the year a valid number?
var intYear = parseInt(strYear, 10);
if (isNaN(intYear))
return false;
if (!IsValidDate(intDay, intMonth, intYear))
return false;
// Okay, reformat the date in the input field, and return
if (strDatestyle == "US") {
objName.value = strMonthArray[intMonth-1] + " " + intDay + " " + strYear;
} else {
objName.value = intDay + " " + strMonthArray[intMonth-1] + " " + strYear;
}
return true;
}
function IsLeapYear(intYear) {
if (intYear % 100 == 0) {
return (intYear % 400) == 0;
} else {
return (intYear % 4) == 0;
}
}
function IsValidMonth(intMonth) {
return (intMonth >= 1 && intMonth <= 12);
}
function IsValidDate(intDay, intMonth, intYear) {
if (!IsValidMonth(intMonth))
return false;
// If day is outside 1-31, there's no way it's valid
if (intDay > 31 || intDay < 1)
return false;
// Check the 30-day months
if (intMonth == 4 || intMonth == 6 || intMonth == 9 || intMonth == 11)
return intDay <= 30;
// Check February's funky days
if (intMonth == 2)
return intDay <= 28 || (IsLeapYear(intYear) && intDay == 29);
return true;
}
function splitDateParts(strDate) {
var strSeparatorArray = new Array("-"," ","/",".");
// Try the various separators out
for (var intElementNr = 0; intElementNr < strSeparatorArray.length; intElementNr++) {
if (strDate.indexOf(strSeparatorArray[intElementNr]) != -1) {
var strDateArray = strDate.split(strSeparatorArray[intElementNr]);
if (strDateArray.length == 3)
return strDateArray;
}
}
// If none were good, assume it's just all numeric
if (strDate.length >= 6)
return new Array(strDate.substr(0, 2), strDate.substr(2, 2), strDate.substr(4));
}
function doDateCheck(from, to) {
if (Date.parse(from.value) > Date.parse(to.value)) {
if (from.value == "" || to.value == "")
alert("Both dates must be entered.");
else
alert("To date must occur after the from date.");
}
}
function placeFocus() {
var acceptableElements = 'text select-one select-many';
if (document.forms.length > 0) {
var fields = document.forms[0];
for (i = 0; i < fields.length; i++)
if(fields.elements[i].type)
if(acceptableElements.toString().indexOf(fields.elements[i].type) >= 0)
return document.forms[0].elements[i].focus();
}
}