Users credentials?

Hi, I would like to know if is possible to do this simple app: Like a hotspot, the basic operation is u create user credentials(username+password), them user make the connection to your wifi network and the system request the credentials. I would like to know if I can send in the backgroud the user credentials? I mean, once the user access our network, if he click 1 button the system let him navigate, the click operation is to send a username+password automatically, can freeradius let me send this credentials with a php app in the background? Last question, can I close user connection went ever I want to? example, if user don't accept our terms close his connection automatically. Is possible? FreeRADIUS 2.x. Thanks!!!