Cleaning My Imac 27'' Screen Safely Please Help

Ok So I Use the soft wipe i got with my imac but after few months now its getting a bit more dirty than a bit of dust and could ideally do with a spray or wipe or somthing

could somone recommend me a cleaning method i could get locally

here is my local computer shop here is some of there cleaning products for computers would you recommend anything they have to offer?

Eclipse Computers - Products

Please Advise Me As after spending the money i did on my computer this kinda thing worrys me and leaves me on edge lol

<3 cheers

I just shut down and unplug my iMac, dampen the cloth that came with it, wipe and get a dry cloth to take the streaks off, clean as new!