Write ajax function to repetitively call cgi until success code is returned

I need an ajax function that does the following: - has 3 parameters: companies_id, subclient_id, span_name - calls a cgi [login to view URL] - if cgi returns 0, replace image in span id=pdf_image2 with different image ([login to view URL]), and waits/sleeps for 5 seconds then calls the [login to view URL] url again. this needs to loop, waiting 5 seconds each time, until a) get a non-zero response, or b) 2 minutes have elapsed - if the cgi returns 1, replace the current span with a) an image, and b) a new link image ([login to view URL]) and url ([login to view URL]), and Base html: <span id="pdf_image2"><input alt="Convertir a PDF" type="image" src="[login to view URL]" width=10 height=11 onClick="javascript:gen_pdf(\'424\',\'63618202\',\'pdf_image2\')"></span> Some crappy attempts i made to get this to work (with the html above inline): [login to view URL] notes: needs to work in internet explorer 8 and greater, firefox, chrome must have as minimal browser impact possible must close every cgi session between 5 second calls...