gistfile1.js

function foo( bar ) {
    
	jQuery.data(document.body, 'response', 4);
    
    if ( bar )
    {
		
        $.get('/something.php', function(response) {
			jQuery.data(document.body, 'response', response);
        });
    }
    
    return 	jQuery.data(document.body, 'response');
}

document.write(foo(1));