"undefined" is appearing in the drop down list when it is not wanted

I have made a drop down list that is populated with months. However, I keep getting the word ‘undefined’ appearing in the drop down list too. Any help is appreciated. Thanks.

// JavaScript Document
var month = ‘
January:January|
February:February|
March:March|
April:April|
May:May|
June:June|
July:July|
August:August|
September:September|
October?ctober|
November:November|
December?ecember|
‘;

// Save the month & state field names
var monthFieldCfgArray = document.getElementById(‘cs_config_month_field’).value.split(‘ ‘);

// Save the names of the fields that hold the month & state default values
var monthDefaultCfgArray = document.getElementById(‘cs_config_month_default’).value.split(‘ ‘);

var defaultMonth = false;

function TrimString(sInString) {

if ( sInString ) {

sInString = sInString.replace( /^s+/g, “” );// strip leading
return sInString.replace( /s+$/g, “” );// strip trailing

}
}
// Populates the month select with the months from the month list
//
function populateMonth(idName) {

var monthLineArray = month.split(‘|’); // Split into lines

var selObj = document.getElementById( idName );

selObj.options[0] = new Option(‘Month’,”);
selObj.selectedIndex = 0;

for (var loop = 0; loop < monthLineArray.length; loop++) {

lineArray = monthLineArray[loop].split(‘:’);

monthCode = TrimString(lineArray[0]);
monthName = TrimString(lineArray[1]);

if ( monthCode != ” ) {

selObj.options[loop + 1] = new Option(monthName, monthCode);
}

if ( defaultMonth == monthCode ) {

selObj.selectedIndex = loop + 1;
}

}
}
// Initialize the drop downs
//
function initMonth() {

for (var loop = 0; loop < monthFieldCfgArray.length; loop++) {

monthIdName = monthFieldCfgArray[loop];

// Read the default value hidden fields
defaultMonth = document.getElementById( monthDefaultCfgArray[loop] ).value;

populateMonth( monthIdName);

}
}

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