How to inform a web page that a submitted job is ended

Hi all. I apologize if an answer to my question already exists but as the
search engine is still not working I couldn't find any post on this
subject. Also, I know very little about communications between iSeries and
external HTTP server.

The scenario consists of a web page run by an IIS HTTP server which makes a
call to a stored procedure on our iSeries; the stored procedure is an RPGLE
program which submits a job under QBATCH subsystem: having the job
submitted is an obliged option because it takes a lot for it to complete.

When the submitted job ends how can it inform or wake the web page to have
the web page do something else?

So far, I could only think of having the web page continuously pooling the
iSeries until a certain condition is reached, such as a certain row on a
table written by the submitted job before ending its execution, but I am
pretty sure this is a very usual need and it's my lack of knowledge about
how to approach this issue.

Please, can you suggest me how to address this question or where I can find
technical documentation on it?

Thank you very much in advance

Lucia