Adjusting Calendar For Booking Form

I have a javascript calendar which will be used for a booking form. The booking form is for the months of october, november and december.

The code is:
//Global variables
var winCal;
var dtToday;
var Cal;
var MonthName;
var WeekDayName1;
var WeekDayName2;
var exDateTime;//Existing Date and Time
var selDate;//selected date. version 1.7
var calSpanID = "calBorder"; // span ID
var domStyle=null; // span DOM object with style
var cnLeft="0";//left coordinate of calendar span
var cnTop="0";//top coordinate of calendar span
var xpos=0; // mouse x position
var ypos=0; // mouse y position
var calHeight=0; // calendar height
var CalWidth=208;// calendar width
var CellWidth=30;// width of day cell.
var TimeMode=24;// TimeMode value. 12 or 24
var StartYear =2010; //First Year in drop down year selection
var EndYear = 5; //End Year offset. i.e. Current Year + 5 .....

//use the Month and Weekday in your preferred language.
var MonthName=["October", "November", "December"];
var WeekDayName1=["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
var WeekDayName2=["Monday","Tuesday","Wednesday","Thursday","Friday","Saturday","Sunday"];
The only problem is when I look at the tcalendar in frontpage preview it shows 9 other months as 'undefined'.