Calling web service from html

I have a wcf web service hosted at discountasp. It is working fine in silverlight and from VS, but I would like to run a scheduler to trigger a particular function once a week.

I believe it can be done by calling my service from html using some javascript for help but I havent been able to get any of the examples I looked at working.

Any advice on how to accomplish this?

Can the scheduler call directly into and trigger a service method?

thanks