Sir, please suggest. I could only think of either store in file (which I think is not a good options as I will need to open read it every time just to compare), another is store in browser cookie.

I'm open for any suggestions. This is my first time working on feeds. My entire site were load by perl, and of course I can do read file or read cookie for further decision making before entire page print out. Or I can use ajax if not entire page reload.

A cookie is a file that you'll need to open (even implicitly). You might as well use your own file, which gives you somewhat better control.

Again, maybe. This is a nebulous spec so far. An LWP/Mech agent could have the cookies in memory if it’s run persistently.

hankcoder, I’m not sure I understand your problem. Without a step-by-step, thorough description of what you’re trying to do, flinging spaghetti at it to see what sticks is kind of a waste of your would-be helpers’ time. :P