how to check size of subsites in sharepoint 2007 using Javascript or Jquery?

Hi,

I need to display the size of all the sites in a site collection at the top level site, strictly using JavaScript or JQuery. Is there any sharepoint web service I can use to do the same. I do not have access to the Central Admin.

Please help me with this, I am quite new to SharePoint and not pretty sure how to proceed with this requirement.

Thanks,

Akillis.