theming on new custome module

Hello Sarkar,

I am facing a problem with theming, when i installed a new fresh drupal
and then i create a cusome module like employee,   then functios are
working but theme is not apperaing on those menus. les take an
example:=

function employee_hook() {

path = employee/home

callback = employee_home

}

function employee_home(){

echo "aa";

}

so the problem is "aa"  is apperaing but theme is not coming over this menu,

what should be the problem ?