I want to make a calendar widget which it can pop up

[Paul Chow Ting Bong <paulchow fieldtech com hk>]

Hi all, I want to make a widget that it is a text output/input then 
follow a button with down arrow.

When user press the button the calendar will show and then select the 
date then hide

And the text input can let user input the date directly with checking.

Any existing widget/code is similar this one? Any infomation and idea 
about this?

Thx~