Building a 'availability calender' posted on other websites

Hi, We run some websites where its members can manage an availability calendar. We would like to give our member the possibility to implement the calender upon their own websites, but want to make this as simple as possible for them. Ideally it works via javascript. People implement some script at their website to get a scrollable calendar at that position in their website. Off course we need to be able to let the members 'post' some variables. We hope it's possible to create someting like one does when one implements Google Adwords. Hope to hear from you soon.