[Dmitriyff]

function general(a, b, do_smth){
    var total = a + b;
    if(total>50){
        do_smth();
    }
}

function gUser1(){
    var first_value = 5;
    var second value = 6;

    general(first_value, second value, function() {
          // do smth
    });
}

function gUser2(){
    var first_value = 5;
    var second value = 6;

     general(first_value, second value, function() {
          // do smth else
     });
}