{1.0.2} reset all settings just what does it do?

I have an unlocked US iPhone version 1.0.2 in the UK.

I am having problems with the BBC iplayer as it keeps asking for flash player to be installed. I have been told to clear Safari history, cookies and cache in settings. Then general > reset > reset all settings.

Am I safe to do this? What will I loose - will it reset back to factory settings or still remain unlocked? Scared to hit that button. Will I need to do anything after, I know I may have to re enter WiFi settings and Edge settings. But I don't want to mess it up completely.

Any help would be appreciated.

Cheers.

you wont loose any apps music or data, its safe and you will remain unlocked, also serach next time and read my signature and the stickys before posting

No, it's not going to relock your phone, but I would suggest seeing if just resetting the safari settings works first before doing all the settings.