mgukov,
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>blank</title>
<script type="text/javascript">
function multiple_selected(a) {
a = a.options;
for (var c = [], b = 0; b < a.length; b++)
a[b].selected && c.push(a[b].value);
//a[b].selected && c.push(a[b]);
return c;
};
</script>
</head>
<body>
<select id="select1" multiple="multiple" size="5" onclick="alert(multiple_selected(this));">
<option value="1">1</option>
<option value="2">2</option>
<option value="3">3</option>
<option value="4">4</option>
<option value="5">5</option>
</select>
</body>
</html>