need help with cfg edit

i cant get cfg edit working. I try inputting a gauge a purple box appears...it's not giving me the gauge preview. can anypost tutorial of a upgrade pack or just help me out. 
i rilly need this for the plane im building.
Is there a other free panel program not for making gauges just for "panels making"

i rilly need this for the plane im building.
Is there a other free panel program not for making gauges just for "panels making"