dhtmlx calendar

I have included scripts dhtmlxcalendar.js and dhtmlxcommon.js and the following ()

in my webpage . But when i try to run the page im getting a script error saying object required . Can some one help

The first line
>> mCal = new dhtmlxCalendarObject(‘dhtmlxCalendar’,
mean that you want to render calendar inside some object with ID='dhtmlxCalendar’
Please be sure that object with such ID exists and script called after such object rendered.