<script language = 'Javascript'>
/**
* DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/datevalidation.asp)
*/
// Declaring valid date character, minimum year and maximum year
var dtCh= '/';
var minYear=1900;
var maxYear=2100;
function isInteger(s){
var i;
for (i = 0; i < s.length; i++){
// Check that current character is number.
var c = s.charAt(i);
if (((c < '0') || (c > '9'))) return false;
}
// All characters are numbers.
return true;
}
function stripCharsInBag(s, bag){
var i;
var returnString = '';
// Search through string's characters one by one.
// If character is not in bag, append to returnString.
for (i = 0; i < s.length; i++){
var c = s.charAt(i);
if (bag.indexOf(c) == -1) returnString += c;
}
return returnString;
}
function daysInFebruary (year){
// February has 29 days in any year evenly divisible by four,
// EXCEPT for centurial years which are not also divisible by 400.
return (((year % 4 == 0) && ( (!(year % 100 == 0)) || (year % 400 == 0))) ? 29 : 28 );
}
function DaysArray(n) {
for (var i = 1; i <= n; i++) {
this[i] = 31
if (i==4 || i==6 || i==9 || i==11) {this[i] = 30}
if (i==2) {this[i] = 29}
}
return this
}
function isDate(dtStr){
var daysInMonth = DaysArray(12)
var pos1=dtStr.indexOf(dtCh)
var pos2=dtStr.indexOf(dtCh,pos1+1)
var strMonth=dtStr.substring(0,pos1)
var strDay=dtStr.substring(pos1+1,pos2)
var strYear=dtStr.substring(pos2+1)
strYr=strYear
if (strDay.charAt(0)=='0' && strDay.length>1) strDay=strDay.substring(1)
if (strMonth.charAt(0)=='0' && strMonth.length>1) strMonth=strMonth.substring(1)
for (var i = 1; i <= 3; i++) {
if (strYr.charAt(0)=='0' && strYr.length>1) strYr=strYr.substring(1)
}
month=parseInt(strMonth)
day=parseInt(strDay)
year=parseInt(strYr)
if (pos1==-1 || pos2==-1){
alert('The date format should be : mm/dd/yyyy')
return false
}
if (strMonth.length<1 || month<1 || month>12){
alert('Please enter a valid month')
return false
}
if (strDay.length<1 || day<1 || day>31 || (month==2 && day>daysInFebruary(year)) || day > daysInMonth[month]){
alert('Please enter a valid day')
return false
}
if (strYear.length != 4 || year==0 || year<minYear || year>maxYear){
alert('Please enter a valid 4 digit year between '+minYear+' and '+maxYear)
return false
}
if (dtStr.indexOf(dtCh,pos2+1)!=-1 || isInteger(stripCharsInBag(dtStr, dtCh))==false){
alert('Please enter a valid date')
return false
}
return true
}
function ValidateForm(){
var dt=document.frmSample.txtDate
if (isDate(dt.value)==false){
dt.focus()
return false
}
return true
}
</script>
<form name='frmSample' ><input type='text' name='txtDate' maxlength='10' size='15'>
<input type='button' value='Submit' onclick='ValidateForm()'>
</form>
