im sure im probley asking a stupid question

but how do you go onto the second level of the campain iv set up the campain selected my troops for the first level did the thing where you decide where to start off then pushed done and started the level but after i finish the the mission push continue and save the game dosent atimaticly minimize (im unsure if its supposed to) so i ctrl alt delete out the game or alt tab but there isnt a screen to sellect troops for next operation the only options are start new campain edit map edit operations or quit nothing saying select troops or any thing iv tried restarting the level but it just restarts the level and iv tried several other things but none of them have worked

so if some one has an answer to a step im missing or something im not doing please reply.