AJAX :: Previous And Next Arrow Is Not Working In Calenderextender Plus?

i am working with ajax calenderextender plus.the prev and next arrow is displaying in calender but when i clickon arrow it is not working.

my code:

<td style="width:50%; height:20px;" >
<asp:TextBox ID="TextBox1" runat="server" style="width:98%; " TabIndex="2" ReadOnly="true">
</asp:TextBox>
<cc2:CalendarExtenderPlus ID="TextBox1_CalendarExtenderPlus" runat="server" ShowDdlHeader="true"
Enabled="true" TargetControlID="TextBox1" WorkWeekLastDay="Saturday"
ShowArrows="true" Format="dd/MM/yyyy">
</cc2:CalendarExtenderPlus>
</td>

my code behind code is:

protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
TextBox1_CalendarExtenderPlus.MaximumDate = DateTime.Today.AddMonths(6);
TextBox1_CalendarExtenderPlus.MinimumDate = DateTime.Today.AddMonths(-6);
}
}