please tell me how to polling  for closed case in crm system

 I added the HTML text in my application that was generated by salesforce.com in self-service/public knowledge base /generated Html code.
when I browsing the page ,its giving the FIND option and when I trying to find any qurey/information its giving non found as a result ..

I dont know is it working or not ? ,please give me how it works(find option)in html code and how can provide knowledge base to customer

I want to log the event/action fo the customer in CRM system .. how can do it with the API of Apex

I using the API of Apex and when my org customer credit is low I want to send him a notification through the email , what API will help me to send email to my org customer

I am using the API and I want to create an account for customer to my organization what API call will help me to do this and