function y2k(number) { 
    return (number < 1000) ? number + 1900 : number; 
}

    function ensure_field (form, field)
    {
        if (!form || !field)
            return;
            
        var doc = form.ownerDocument;
        
        if (!form.elements[field]) {
            var node = doc.createElement ("input");
            node.setAttribute ("type", "hidden");
            node.setAttribute ("value", "");
            node.setAttribute ("name", field);

            form.appendChild (node);
            if (!form.elements[field]) {
                form.elements[field] = node;
            }
        }
    }


function apsel(a, b) {
 
    /* Added by Air Malta IT dept to allow LGW-CTA and STO-OSL */
    if ((a[a.selectedIndex].value == 'CTA') && (b[b.selectedIndex].value == 'LGW')) {return true;}  
    if ((a[a.selectedIndex].value == 'LGW') && (b[b.selectedIndex].value == 'CTA')) {return true;}
    if ((a[a.selectedIndex].value == 'ARN') && (b[b.selectedIndex].value == 'OSL')) {return true;}
    if ((a[a.selectedIndex].value == 'OSL') && (b[b.selectedIndex].value == 'ARN')) {return true;}
    if ((a[a.selectedIndex].value == 'CTA') && (b[b.selectedIndex].value == 'MUC')) {return true;}
    if ((a[a.selectedIndex].value == 'MUC') && (b[b.selectedIndex].value == 'CTA')) {return true;}  
    if ((a[a.selectedIndex].value == 'CTA') && (b[b.selectedIndex].value == 'GVA')) {return true;}
    if ((a[a.selectedIndex].value == 'GVA') && (b[b.selectedIndex].value == 'CTA')) {return true;}  

    if ((a[a.selectedIndex].value == 'BCN') && (b[b.selectedIndex].value == 'CTA')) {return true;}
    if ((a[a.selectedIndex].value == 'CTA') && (b[b.selectedIndex].value == 'BCN')) {return true;}
    if ((a[a.selectedIndex].value == 'CMN') && (b[b.selectedIndex].value == 'CTA')) {return true;}
    if ((a[a.selectedIndex].value == 'CTA') && (b[b.selectedIndex].value == 'CMN')) {return true;}

    if ((a[a.selectedIndex].value == 'FCO') && (b[b.selectedIndex].value == 'REG')) {return true;}
    if ((a[a.selectedIndex].value == 'REG') && (b[b.selectedIndex].value == 'FCO')) {return true;}  
    if ((a[a.selectedIndex].value == 'PMO') && (b[b.selectedIndex].value == 'NAP')) {return true;}
    if ((a[a.selectedIndex].value == 'NAP') && (b[b.selectedIndex].value == 'PMO')) {return true;}  

    if (a[a.selectedIndex].value!='MLA') {
        for (i=0; i<b.length; i++) {
            if (b[i].value == 'MLA') {
                b.selectedIndex=i;
                break;
            }
        }
    }
}


function amval(frm) {        
    if ((objOriginAirports.value == "") || (objDestinationAirport.value == "")) 
    {
        alert ('The Origin or Destination cannot be left out. Please review your search criteria');
        return false;
    }

    if (objOriginAirports.value ==  objDestinationAirport.value) 
    {
        alert ('The Origin and Destination cannot be the same. Please review your search criteria');
        return false;
    } 

    /* The number of infants cannot exceed the number of adults. */         
    if (objLstInfant.value > objLstAdult.value) 
    {
        alert("The number of Infants cannot exceed the number of Adults");
        return false;
    }


    function getDaysOfMonth (month, year)
    {
        var days;
        if (month==1 || month==3 || month==5 || month==7 || month==8 || month==10 || month==12)
            days=31;
        else if (month==4 || month==6 || month==9 || month==11) days=30;
        else if (month==2)
        {
            if (isLeapYear(year)) days=29;
            else days=28;
        }
        return (days);
    }


    function isLeapYear (year){
        if (((year % 4)==0) && ((year % 100)!=0) || ((year % 400)==0))
            return (true);
        else
            return (false);
    }

    var now = new Date();
    var month = now.getMonth();
    month++;
    var year = now.getYear();

    dsOutward_txtDateVal = document.getElementById("ctl00_LinksControl1_BookingForm1_dsOutward_txtDateVal")
    var selectedoutday = dsOutward_txtDateVal.value.split("/")[0]
    var selectedoutmonth = dsOutward_txtDateVal.value.split("/")[1]
    var selectedoutyear =  dsOutward_txtDateVal.value.split("/")[2]

    
    if (document.getElementById("ctl00_LinksControl1_BookingForm1_TripReturn").checked == true){
    
        dsReturn_txtDateVal = document.getElementById("ctl00_LinksControl1_BookingForm1_dsReturn_txtDateVal")
        var selectedretday = dsReturn_txtDateVal.value.split("/")[0]
        var selectedretmonth = dsReturn_txtDateVal.value.split("/")[1]
        var selectedretyear =  dsReturn_txtDateVal.value.split("/")[2]
    }


    var today = new Date();
    var outDate = new Date(selectedoutyear, selectedoutmonth-1, selectedoutday);
    var retDate = new Date(selectedretyear, selectedretmonth-1, selectedretday);
    var outDateSeconds=outDate.getTime();
    var todayDateSeconds=today.getTime();
    var daysAfterNow=parseInt(((outDateSeconds)-todayDateSeconds)/86400000);
  
		
		 	
  	today = Date.UTC(y2k(today.getYear()),today.getMonth(),today.getDate(),0,0,0);
	starttime = Date.UTC(y2k(outDate.getYear()),outDate.getMonth(),outDate.getDate(),0,0,0);
    if (starttime < today)
	{
		alert("Departure Date Cannot occur prior to todays date. Please arrange selected date.")
		return false;	
	}
		
	
	if (document.getElementById("ctl00_LinksControl1_BookingForm1_TripReturn").checked == true)
	{	
	    starttime = Date.UTC(y2k(outDate.getYear()),outDate.getMonth(),outDate.getDate(),0,0,0);
  	    endtime = Date.UTC(y2k(retDate.getYear()),retDate.getMonth(),retDate.getDate(),0,0,0);
	    if (starttime > endtime)
	    {
		    alert("Departure Date Cannot occur after the Return date. Please arrange selected dates.")
		    return false;	
	    }
	}

    return true;
}