/**
 * DHTML date validation script. Courtesy of SmartWebby.com (http://www.smartwebby.com/dhtml/)
 */
// 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
}

    //start new script code
    // Checks if browser is Netscape 2.0x since the options array properties don't work with Netscape 2.0x
    function isBrowserSupp() {
        // Get the version of the browser
        version =  parseFloat( navigator.appVersion );

        if ( ( version >= 2.0 ) && ( version < 2.1 ) && ( navigator.appName.indexOf( "Netscape" ) != -1 ) ) {
            return false;
        } else {
            return true;
        }

        return true;
    }

    function isLeapYear( yrStr ) {
        var leapYear = false;
        var year = parseInt( yrStr, 10 );
        // every fourth year is a leap year
        if ( year % 4 == 0 ) {
            leapYear = true;
            // unless it's a multiple of 100
            if( year % 100 == 0 ) {
                leapYear = false;
                // unless it's a multiple of 400
                if( year % 400 == 0 ) {
                    leapYear=true;
                }
            }
        }
        return leapYear;
    }

    function getDaysInMonth( mthIdx, YrStr ) {
        // all the rest have 31
        var maxDays = 31
        // expect Feb. (of course)
        if( mthIdx == 1 ) {
            if( isLeapYear( YrStr ) ) {
                maxDays=29;
            } else {
                maxDays=28;
            }
        }

        // thirty days hath...
        if( mthIdx == 3 || mthIdx == 5 || mthIdx == 8 || mthIdx == 10 ) {
            maxDays=30;
        }
        return maxDays;
    }

    //the function which does some magic to the date fields
    // return non-zero if it is the last day of the month
    function adjustDate( monthObj, dayObj, yearObj ) {
        var value = 0;
        var mthIdx = monthObj.options.selectedIndex;
        var Dt = dayObj;
        var theYear = yearObj.options[yearObj.options.selectedIndex].value;

        var numDays = getDaysInMonth( mthIdx, theYear );

        if( mthIdx == 1 ) {
            if( Dt.options.selectedIndex + 2 < numDays ) {
                return 0;
            } else {
                if( Dt.options.selectedIndex + 1 > numDays) {
                    Dt.options.selectedIndex=numDays - 1;
                }
                //check for leap year
                if( (Dt.options.selectedIndex + 1) == numDays ) {
                    return 1;
                } else {
                    return 4;
                }
            }
        }

        if( Dt.options.selectedIndex + 2 < numDays ) {
            value = 0;
        } else {
            if ( Dt.options.selectedIndex + 1 > numDays ) {
                Dt.options.selectedIndex--;
                value = 3;
            } else if ( Dt.options.selectedIndex + 1 == numDays ) {
                //index is 31 or 30
                value = 2;
            } else {
                value = 4;
            }
        }
        return value;
    }

    //changes departure month when arrival month is changed
    function amadChange( inM, inD, inY ) {
        if ( !isBrowserSupp() ) {
            return;
        }
        var res = adjustDate( inM.options.selectedIndex, inD, inY.options[inY.options.selectedIndex].value );
        return;
    }

    function dmddChange( outM, outD, outY ) {
        if ( !isBrowserSupp() ) {
            return;
        }

        adjustDate( outM.options.selectedIndex, outD, outY.options[outY.options.selectedIndex].value );
        return;
    }