验证码更换

<td style="width: 174px; height: 8px;">
                    验证码：</td>
                <td style="width: 381px; height: 8px;">
                    <asp:TextBox ID="txtCode" runat="server" Width="49px"></asp:TextBox>
                <SCRIPT type=text/javascript>                                        /*<![CDATA[*/
                                        document.write('<img id="MzImgExpPwd" alt="" src="../checkcode.aspx" />');
                                        /*]]>*/</SCRIPT>
           
         
                   <A  style="font-size:12px;color:Black"
            onclick="document.getElementById('MzImgExpPwd').src='../checkcode.aspx?temp='+ (new Date().getTime().toString(36)); return false"
            href="#">更换</A></td>