multi month calendar

[Bharathi vallab]

I am learning Java script and trying to display 2 calendars (current month and previous month)
2)If I select < then current month should be next month and previous month should be be current month .just oppsite with >
3) I should have a dropdown(with month/year selection) on the top of the page .based on the month or year selected that month/year calendar current month calendar should be replaced with selected month and previous month should be previous month of selected month
4) weeks and days with hyperlinks.so when I click link it should open new window with url.

Could you please suggest me how can I work on this.I am very little knowledge of javascript.