?
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
<title>Navigation</title>
<style type="text/css">
<!--
body {
margin: 0;
padding: 4px;
font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif;
font-size: 12px;
background-color: #6E89DD;
color: #FFFFFF;
text-align:center;
font-weight:bold;
}
input, select {
font-family: Tahoma, Verdana, Arial, Helvetica, sans-serif;
font-size: 12px;
font-weight:normal;
}
-->
</style>
<script language="JavaScript">
<!-- hide
function change_page()
{
top.mainFrame.location= document.periodForm.periodSelect.value + '/index.html';
}
// -->
</script>
</head>
<body>
<form name="periodForm" action="" method="get">
Select period
<select name="periodSelect" ONCHANGE="change_page()">
<option value="current">Current</option>
<option value='2018-05'>2018-05</option>
<option value='2018-06'>2018-06</option>
<option value='2018-07'>2018-07</option>
<option value='2018-08'>2018-08</option>
</select>
</form>
</body>
</html>