I did not tested this with different browsers, but if you do this in Chrome and jQuery 1.9:

```
function bar() {
    $.ajax({
        async   : false,
	url     : someurl.com,
	complete: function (XMLHttpRequest, textStatus) {
            return true;
        }
    });
}
var foo = bar();
```

foo will be undefined at the end. Therefore bar() has to have a return statement.