Hey. ive worked with photoshop a little bit but only in "RGB mode". GIF images use "indexed colour" mode so have no idea how im suposed to add some transparency to an existing image. Thnx in Advance!

First make sure the lowest layer is a layer and not a background. If it's a background, select it and go Layer > New > Layer From Background. Select everything you want to be transparent and hit delete. Then go File > Save for Web & Devices. Make sure Transparency is ticked. Choose how many colours you want and Save.

Adding transparency to a gif is as simple as selecting the color for it. But be aware you can't legally release any gif image without a license. I would suggest you use png since it is a freely distributable format, it's 24 bit (16 billion colors) (gif 8 bit, 256 colors) and it supports compression and an alpha channel (256 transparency levels).

Thnx abstrationline that works fine.

LancerSolurus: i allready use TGA for all textures in my game so im not realy looking for a new format or anything i just wanted to use a 32x32 GIF for the little icon on my window if my game runs in window'd mode (which it normaly wont but the user can choose to if he wants to). GIF was just the simplest solution since java natively supports it. If it realy isnt legal il just use my engines TGA loader to to load a TGA and convert it to a Java image and then use that. But could you maybe explain a little more about GIF licencing? and is this realy illegal in my specifick case?