Question

The issue I am having is I cannot access the value of the variables outside the function. I have just started to learn jQuery and I really like it, but this has had me stuck for quite a while now.

I have read other threads related to this, but those methods still do not work!

    $.get("/new/verify.php", { username: username, email: email },
        function(data){
            var stop_loading = '0';
            if(data == 'username')
            {
                alert('username taken');
                $('#username_taken_error').show();
                $('#username').focus();
                stop_loading = '1';
            }else if(data == 'email') {
                alert('email taken');
                $('#email_taken_error').show();
                $('#email').focus();
                stop_loading = '1';
            }else if(data == 'username|email') {
                alert('username/email taken');
                $('#username_taken_error').show();
                $('#email_taken_error').show();
                $('#username').focus();
                stop_loading = '1';     
            }
    });

    alert(stop_loading);

    if(stop_loading == '1') {
        alert('Stop loading');
        return false;   
    }

Answer 1

As $.get() performs an AJAX request which is asynchronous, so within your $.get() success function call another function with your stop_loading like following:

 $.get("/new/verify.php", { username: username, email: email },
        function(data){
            var stop_loading = '0';
            if(data == 'username')
            {
                alert('username taken');
                $('#username_taken_error').show();
                $('#username').focus();
                stop_loading = '1';
            }else if(data == 'email') {
                alert('email taken');
                $('#email_taken_error').show();
                $('#email').focus();
                stop_loading = '1';
            }else if(data == 'username|email') {
                alert('username/email taken');
                $('#username_taken_error').show();
                $('#email_taken_error').show();
                $('#username').focus();
                stop_loading = '1';     
            }
            // call function with stop_loading
            callAFunction(stop_loading);
    });

    // this function will be called
    // with stop_loading arugment

    function callAFunction(stop_loading){
      if(stop_loading == '1') {
        alert('Stop loading');
        return false;   
      }
    }