calendar control binding to a variable of type date

Hi,

I have a column with date datatype in my DB. from a website, i am using a calendar control (using ajax) and i need to bind the value of the selected calendar to a variable of type date and then store it in db.

I am using the following code in html and in my .vb page but getting exceptions everytime.

Please help me:
<b>
<u>html page:</u></b>

 <asp:CalendarExtender ID="CalendarExtender1" runat="server" TargetControlID="txtbx_req_prod_date" Format="MM/dd/yyyy"></asp:CalendarExtender>
<asp:TextBox ID="txtbx_req_prod_date" runat="server"></asp:TextBox>

<b><u>vb page:</u></b>

Dim Req_prod_date As Date
txtbx_req_prod_date.Text = CalendarExtender1.SelectedDate.ToString()
Req_prod_date = txtbx_req_prod_date.ToString()

Qry = "Insert into myshemaname.mytablename" & _
              "(column_name)" & _
              "values ('" & Req_prod_date & "')"

then i use command.executenonquery and stuffs to insert this.....


Thanks in advance