Magento

Hi

I would like to change sembols like these $ € £ showing next to prices lists.,could you pelase tell me where can I change them? 

and also Our currency is look like TRY but I like to change that to YTL,How can I change these?TRY is not the right one. thansk very much

Juron

// EDIT

Symbol and Currency files in

\lib\Zend\Locale\Data

Thank you....

Thank you problem fixed..

Thanks for that,
I have an issue when £ and & currencies on the product price are displayed, when the site is viewed in French, as $ US 34.00 and £UK 23.00
In my french language file (downloaded from Magento) i have the following the following:
$ US and £UK instead of £ and $
So I deleted the spare characters from fr.xml in the \lib\Zend\Locale\Data directory and it still does not work…
I am lost here...any help?
Manu