return true from function in function [duplicate]

I'd like to return true from a function in a function. Here is the code for better understanding:

function abc() {
   form = $('form');
   formData = form.serialize();

    $.post('../control/request.php', formData, function(result) {
        return true;
    });
}

if (abc()) {
    // true
} else {
    // false
}