So I want to resize gif since its height is above limitation for what I need.

It's this:

http://27.media.tumblr.com/tumblr_ln...vjn8o1_400.gif


I need the height to be 100x....and same proportion.

Please someone help me. :[

I have Photoshop but I don't know how to do gifs with it, I can edit images tho.

File > Import > Video Frames to Layers

Easy.

Save the gif on your computer.
Open Photoshop.

OPEN
File > Open
Go to the file location in the Open dialog.
If you can't see the file in the folder where you saved it, type "*.gif" (without the quotes) into the file name box.
Open the gif.

RESIZE
Command/Control + Alt + I
Change the image size.

SAVE
File > Save for Web and Devices
Click Save.

Done.

Open the gif in Photoshop normally.
On the main menu you should see a Tab that says Image .
Go to Image Size and make it the way you want.
Then go to File and Save For Web And Devices.

If I open it it says 'this is an animated gif you can only view 1 frame'

Did you do what Seems said or what I said?
If you saved the gif directly to you computer then you should be able to open it.