Javascript Check Login function returns false, but continues to next line anyways?

Javascript Check Login function returns false, but continues to next line
anyways?

The following code checks for a user and returns false if the user is not
logged in.
function checkLogin(e) {
loggedIn = $('#loggedin').text();
if(loggedIn == '1'){
e.preventDefault();
alert("Please Log In");
return false;
}
}
I then call this function before some other code and an ajax call.
tileFavorite = $('.tileFavorite');
tileFavorite.on('click', function(e) {
checkLogin(e);
//some code goes here before ajax call
$.ajax({
url: // ajax call goes here,
cache: false
})
});
The check login actually works. However if the checkLogin function returns
false, it still continues to the code beneath it. There a way to avoid
this?