Q:

Uncaught ReferenceError: function Post() is not defined

I use JS and Jquery functions:
//Jquery
$(function(){

  function Post(id) {
    $.post('index.php', {
            id: id
            },function (data) {alert(data) });
}  
});

//Javascript

Func.addCallback('onSuccess', function(id) {

 Post(id);
}

I get error when use code:
Uncaught ReferenceError: wallPost is not defined

I  know that error becose function javascript use function jQuery, but how remove error? 

A:

You should defined the Post function outside of the $(document).ready callback or it won't be visible to the outside:
function Post(id) {
    $.post('index.php', { id: id }, function (data) {alert(data) });
}

//Jquery
$(function() {
    // this will execute when the DOM is ready
});

//Javascript
Func.addCallback('onSuccess', function(id) {
    Post(id);
}

If on the other hand you are attempting to use jQuery with other js frameworks that might be hijacking the $ function you may take a look at the corresponding section in the documentation: http://api.jquery.com/jQuery.noConflict/

