Multiple checkbox value will show in textbox
===

Here is my code :

    <body>
    <div align="center">
    <b>A<input type="checkbox" name="a" id="check" value="a"></b>
    <b>B<input type="checkbox" name="b" id="check" value="a"></b>
    <b>B<input type="checkbox" name="c" id="check" value="c"></b>
    <b>D<input type="checkbox" name="d" id="check" value="d"></b>
    </div>
    <table align="center">
    <tr>
    <td>Text:</td>
    <td><input type="text" name="text" id="text"></td>
    </tr>
    </table>
    </body>

I'm trying that: ifr (more than one)checkbox is selected(or checked) that value will be assigned into the checkbox like "abcd" or "acd" or "bd".For that I have written jquery

    <script type="text/javascript">
    $(document).click(function(){
	if($("#check").attr('checked')){
		$("#text").val(("#check").val());
	}
    });
    </script>

able to print one txtbox value at a time,but not able to put all checked value in the textbox at a time.
Where I am going wrong ??Any inputs will appreciated.