Question

How to make 1st function back_a with popstate inside remove after click,
then I can run antoner?

function back_a(){
    $(window).bind('popstate', function(e){
        //do some thing
    });
}
back_a();

function back_b(){
    $(window).bind('popstate', function(e){
        //do different thing
    });
}

$('btn').click(funcion(){
    // how to cancel back_a();
    //run back_b();
    back_b();
});

Answer 1

Events in jquery can be namespaced:

$(selector).on("click.myclick", function(){...});

You can remove just that particular event later by doing:

$(selector).off("click.myclick");

Edit

Try something like this:

$(window).on("popstate.fubar", function(e){
    // do some stuff here
});

$('btn').click(funcion(){
    $(window).off("popstate.fubar");
    $(window).on("popstate.fubar", function(e) {
        // do some different stuff here
    });
});​