Ok when i click on an button with the class "allas" i want that jquery appends the text of the button to my input with the id "inputbox". So far all works good:

```
$(document).ready(function() {
    $('.allas').click(function() {
        $('#inputbox').val($(this).text());
    });
});

```

But first problem is that my code always replaces the input val, when i click on another button with the class "allas". I want that jquery adds the value seperated by an ; 

And "i think the more difficult part" i want an undo function, that when the user clicks again on an button that he yet has pressed the value of the button should be delted from the input!

I hope you understand me? Thanks for help!

<http://jsfiddle.net/WcCTe/>