Question

function checkSession(){
    $.ajax({url: "session.php", success: function(data){
         if( data == 1){
             var postFilen = 'msg.php';
             $.post(postFilen, function(data){
                 $("#msg").html(data).find("#message2").fadeIn("slow")
            }
         } else {
             $('#message2').hide();
         }
    }});
// setInterval('checkSession()',1000);
}

Basically, this is checking if data is 1 in session.php, and if it is, it should run msg.php´s div #message2 in #msg

Answer 1

If you formatted your code more logically it would be clearer what your intentions were with this.

In your $.post() call, you close the curly brace on the function, but you don’t close the $.post() paren.

Replace:

$.post(postFilen, function(data){
    $("#msg").html(data).find("#message2").fadeIn("slow")
}

with:

$.post(postFilen, function(data){
    $("#msg").html(data).find("#message2").fadeIn("slow");
});

Edit: This is what I mean by properly format:

function checkSession() {
    $.ajax({url: "session.php", success: function(data){
        if(data == 1) {
            var postFilen = 'msg.php';
            $.post(postFilen, function(data){
                $("#msg").html(data).find("#message2").fadeIn("slow");
            });
        } else {
            $('#message2').hide();
        }
    }});
}