// Declaring valid date character, minimum year and maximum year
var dtCh= "/";


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 (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.EmploymentApplication.Date
        if (isDate(dt.value)==false){
                dt.focus()
                return false
        }
    return true
 }