change a launcher's icon...

[Remotes]

hi, i'm trying to change the icon associated to a launcher on xfce4-panel...

i'd like to make a little bash script to connect/disconnect to the net and i 
would like that the icon changes automatically if the connection is up or 
down...

that's not a big problem, i can make an other simple bash script that checks 
the state of the connection and edit the image (just renaming the filename)

but how can i "refresh" the panel to make effective the changes made by the 
script just using a terminal command?

i'm really sorry for my bad english :S 

see ya
-- 
Nicolò "Remotes" Lucia
Debian ETCH (XFCE)
"the 449257th penguin"