google calender

Hi
I am using google calender plugin in my wordpress site. there I faced little problem . I want to show an option

“check for availability”

where people input the date and press then he should see if this date has an event or not. you can see what i want is like http://musicplacedj.com/ here. it is not on google calender. and its on others things. I just want to see same form like this site. and see have events or not.

thanks