Unable to use the "Alt Gr"-button

Question

Hello,
I've just installed Arch again after being on W7 for 2 last year.
But it seems that the "Alt Gr"-button wont work properly.
I'm using LXDE and I've tried to find an answear about the problem but so far nothing.
The layout I am using is se_SV and the Alt Gr button is essencital for us sweds since it is in the combaination to typ the @-sign.
I believe that the keyboard works properly outside LXDE so I would assume that the problem envolvs around LXDE.
Any ideas?

Answer 1

Solved:
The default xmodmap is useless for swedish keyboards since most keymappings looks like this:
keycode 11 = 2 quotedbl 2 quotedbl at twosuperior
This is the mapping for key the "2". The symbols after the '=' is:
2: produces '2' by typing 2 without modifier
quotedbl: produces '"' by typing 2 with shift
2: produces '2' by typing 2 with Multi_key (Alt_Gr)
quotedbl: produces '"' by typing 2 with shift+Multi_key (Alt_Gr)
The rest of the mappings is unaccesible for my keyboard. See the problem?
Changing the keycode mapping with
xmodmap -e "keycode 11 = 2 quotedbl at twosuperior"
gives
2: produces '2' by typing 2 without modifier
quotedbl: produces '"' by typing 2 with shift
at: produces '@' by typing 2 with Multi_key (Alt_Gr)
twosuperior: produces '²' by typing 2 with shift+Multi_key (Alt_Gr)
To do the same for all relevant keys I kopied the keymap
xmodmap -pke > ~/.xmodmaprc
I edited the ~/.xmodmaprc file like above for all relevant keycodes and then loaded the file with
xmodmap ~/.xmodmaprc
on startup wia the autostart script for the LXDE session