
<html>

<head>

<script language="javascript">

<!--

        var selArray = new Array();

        function checkSelected(selObj){

                for(i=0;i<selObj.length;i++){

                        if(selObj.options[i].selected){

                                if(selArray[i] != "<undefined>" && selArray[i]==true)

                                        selArray[i] = false;                                

                                else

                                        selArray[i] = selObj.options[i].selected;                                

                        }

                }

                for(j=0;j<selArray.length;j++){

                        if(selArray[j])

                                selObj.options[j].selected=true;

                        else

                                selObj.options[j].selected=false;

                }

        }

//-->

</script>

</head>

<body>

<form>


<select name="sel1" multiple style="width:100;height:200" onChange="checkSelected(this)">

<option>One

<option>Two

<option>Three

<option>Four

<option>Five

<option>Six

<option>Seven

<option>Eight

<option>Nine

<option>Ten

</select>

</form>

</body>

</html>