<html>
<head>
<script>
function selectAll(id, isSelected) {
//alert("id="+id+" selected? "+isSelected);
var selectObj=document.getElementById(id);
//alert("obj="+selectObj.type);
var options=selectObj.options;
//alert("option length="+options.length);
for(var i=0; i<options.length; i++) {
options[i].selected=isSelected;
}
}
</script>
<body>
<form>
<select id="s1" name="country" multiple size=5>
<option value="China">China, PRC</option>
<option value="USA">United States of American</option>
</select>
<a href="#" onclick="return selectAll('s1', true)">Select All</a>
<a href="#" onclick="return selectAll('s1', false)">DeSelect All</a>
</form>
</body>
</html>