Where's a good site to book a single flight from London, England to Izmir, Turkey?

All I seem to be able to find are return journeys but I'm just looking for a one-way journey ;D

kayak.com

Please forgive me if it doesn't do international thoughts but that site was right off my head-cheapest one. Maybe orbit.com would work too? Someone probably will have better input than me.

Alrighties, thanks!!
I'll check those sites out this weekend (when my performances are finished!) and see what I find :)