Diffrence b/w AJAX(Click and Script) and Web(Click and Script)


My application is Web application and application has Java Script
I installed LR 9.51 on Windows XP.
Protocol advisor suggests 2 protocols as 1. AJAX (Click and Script) 2.WEB (Http/Html).
I am using Firefox as 3.6.12 version
1. I record the script by using the protocol as AJAX (Click and Script) and IE, Script recorded.
But when I used Firefox, script did not record.
Does LR 9.51 support AJAX (Click and Script) Firefox?
2. When I recorded the script and replayed the script by using WEB (Http/Html (IE and Firefox) it gives error as “This page uses Java Script and requires java script enabled browser. Your browser is not java Script enabled.

3.I record the same operation using protocols AJAX (Click and Script) and Web(Click and Script),While replay the script both gave me the same error "Web button not found .unable to create the step" .
Even I didnot see much difference in code.

a)How to I resove this issue?

b)Is there any difference b/w AJAX (Click and Script) and Web(Click and Script).
Instead of AJAX (Click and Script)can I use Web(Click and Script),even though protocol advisor didnot suggested.

Thanks in advance.