javascript - Single page application with login and search robots -

in work javascript single page application, have run problem. whole idea behind project, avoid page reload. when user comes application won't need make reloads. done jquery , backbone.js , php service.

i have static index.html file, hide login container , application container. show login container, if user not recognize application, , if have auth show application.

if auth:   application.show() elif not auth:   login.show() // gmail or facebook etc.: information + login-form 

i wan't show users aren't authenticated, both login-form , general info. important site can found robots google etc.

can done 2 different files, giving me reload? site.com , login.site.com. solution irritates me, because login, now, quite instant.

not sure question if want check if user in authenticated, try ajax call. if fails "401 unauthorized" user needs login...