only one instance of a scriptmanager can be added to the page

<%@ Page Language="C#" MasterPageFile="~/MasterPage1.master" AutoEventWireup="true" CodeFile="CreatAdverties.aspx.cs" Inherits="CreatAdverties" Title="Untitled Page" %>

<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="cc1" %>

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">

</asp:Content>
<asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server">
    <cc1:ToolkitScriptManager ID="ToolkitScriptManager1" runat="server">
    </cc1:ToolkitScriptManager>
    <asp:Panel ID="Panel1" runat="server">
        <table width="50%" align="center" >
        <tr>
            <td colspan="4" align="center">
                &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<asp:Label ID="lblcreate" runat="server"
                    Font-Bold="True" Font-Names="Arial" Text="Create your Add here "></asp:Label>
            </td>
        </tr>
        <tr>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
            <td>
                &nbsp;</td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblarea" runat="server" Text="Select Area:" Font-Bold="True"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:DropDownList ID="ddlCreateAddArea" runat="server" AutoPostBack="True"
                    onselectedindexchanged="ddlCreateAddArea_SelectedIndexChanged" Width="186px">
                </asp:DropDownList>
            </td>
            <td>
                &nbsp;</td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblctgry" runat="server" Font-Bold="True"
                    Text="Select Category:"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:DropDownList ID="ddlCreateAddCategory" runat="server" AutoPostBack="True"
                    onselectedindexchanged="ddlCreateAddCategory_SelectedIndexChanged" Width="186px">
                </asp:DropDownList>
            </td>
            <td>
                &nbsp;</td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblshopname" runat="server" Font-Bold="True"
                    Text="Shop/Company Name:"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:TextBox ID="txtshopname" runat="server"></asp:TextBox>
            </td>
            <td>
                <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server"
                    ControlToValidate="txtshopname"
                    ErrorMessage="Please Enter the Shop/Company Name">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblshopAddress" runat="server" Font-Bold="True"
                    Text="Shop/Company Address:"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:TextBox ID="txtCadress" runat="server"></asp:TextBox>
            </td>
            <td>
                <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server"
                    ControlToValidate="txtCadress"
                    ErrorMessage="Please Enter the Shop/Company Address">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblshopcity" runat="server" Font-Bold="True" Text="City:"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:TextBox ID="txtCity" runat="server"></asp:TextBox>
            </td>
            <td>
                <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server"
                    ControlToValidate="txtCity" ErrorMessage="Please Enter the City">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td align="right">
                <asp:Label ID="lblcontact" runat="server" Font-Bold="True" Text="Contact No:"></asp:Label>
            </td>
            <td>
                &nbsp;</td>
            <td>
                <asp:TextBox ID="txtcontact" runat="server"></asp:TextBox>
            </td>
            <td>
                <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server"
                    ControlToValidate="txtcontact" ErrorMessage="Please Enter the Contact no">*</asp:RequiredFieldValidator>
            </td>
        </tr>
        <tr>
            <td align="right" class="style3">
                <asp:Label ID="lblemail" runat="server" Font-Bold="True" Text="Email-ID:"></asp:Label>
            </td>
            <td class="style3">
                </td>
            <td class="style3">
                <asp:TextBox ID="txtemail" runat="server"></asp:TextBox>
            </td>
            <td class="style3">
                <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server"
                    ControlToValidate="txtemail" ErrorMessage="Enter the Valid Email-ID"
                    ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*">*</asp:RegularExpressionValidator>
            </td>
        </tr>
        <tr>
            <td align="right" class="style3">
                <asp:Label ID="lblstart" runat="server" Font-Bold="True" Text="StartDate:"></asp:Label>
            </td>
            <td class="style3">
                &nbsp;</td>
            <td class="style3">
                <asp:TextBox ID="txtstart" runat="server"></asp:TextBox>
                <cc1:CalendarExtender ID="CalendarExtender1" runat="server">
                </cc1:CalendarExtender>
            </td>
            <td class="style3">
                &nbsp;</td>
        </tr>
            <%--<tr>
                <td align="right" class="style3">
                    Upload Image:</td>
                <td class="style3">
                    &nbsp;</td>
                <td class="style3">
                    <asp:FileUpload ID="fileuploadimages" runat="server" />
                </td>
                <td class="style3">
                    &nbsp;</td>
            </tr>
            <tr>
                <td align="right" class="style3">
                    Enter Image Desc</td>
                <td class="style3">
                    &nbsp;</td>
                <td class="style3">
                    <asp:TextBox ID="txtDesc" runat="server"></asp:TextBox>
                </td>
                <td class="style3">
                    &nbsp;</td>
            </tr>--%>
            <tr>
                <td align="right">
                    <asp:Label ID="lblEnd" runat="server" Font-Bold="True" Text="EndDate:"></asp:Label>
                </td>
                <td>
                    &nbsp;</td>
                <td>
                    <asp:TextBox ID="txtEnd" runat="server"></asp:TextBox>
                </td>
                <td>
                    &nbsp;</td>
            </tr>
            <tr>
                <td align="right" >
                    &nbsp;</td>
                <td>
                    &nbsp;</td>
                <td>
                    &nbsp;</td>
                <td>
                    &nbsp;</td>
            </tr>
            <tr>
                <td>
                    &nbsp;</td>
                <td>
                    &nbsp;</td>
                <td>
                    <asp:Button ID="btncreat" runat="server" onclick="btncreat_Click"
                        Text="Submit" />
                </td>
                <td>
                    &nbsp;</td>
            </tr>
    </table>
    </asp:Panel>
</asp:Content>