Problem in Update Data in Gridview via SqlDatasource with Store Procedure

Create Proc uspUpdateArticle
@ArticleID int, @Title varchar(50), @Body varchar(1000),
@Author varchar(50), @Categories varchar(30), @Updatedby int
As
BEGIN
SET NOCOUNT ON;
UPDATE TblArticles SET Title = @Title, Body = @Body, Author = @Author, Categories = @Categories, Updatedby = @Updatedby WHERE ArticleID = @ArticleID
END

  <asp:SqlDataSource ID="SqlDataSource1" runat="server" ConnectionString="<%$ ConnectionStrings:ECII(Old)ConnectionString %>" SelectCommand="uspGetArticles" DeleteCommand="uspDeleteArticle"  UpdateCommandType="StoredProcedure" UpdateCommand="uspUpdateArticle" SelectCommandType="StoredProcedure" DeleteCommandType="StoredProcedure">
            <DeleteParameters>
                <asp:Parameter Name="ArticleID" Type="Int32" />
            </DeleteParameters>
            <SelectParameters>
                <asp:SessionParameter Name="PublishedBy" SessionField="UserID" Type="Int32" />
                <asp:SessionParameter Name="SubcriptionId" SessionField="SubscripID" Type="Int32" />
            </SelectParameters>
            <UpdateParameters>
                <asp:Parameter Name="Title" Type="String" />
                <asp:Parameter Name="Body" Type="String" />
                <asp:Parameter Name="Author" Type="String" />
                <asp:Parameter Name="Categories" Type="String" />
                <asp:SessionParameter Name="Updatedby" SessionField="UserID" Type="Int32" />
                <asp:Parameter Name="ArticleID" Type="Int32" />
            </UpdateParameters>
        </asp:SqlDataSource>
        <div style="width: 98%; height: 500px; margin: 0 auto; margin-removed 10px; overflow: scroll;">

<asp:GridView ID="GridViewListallarticles" runat="server" AutoGenerateColumns="False" BackColor="White" BorderColor="#DEDFDE" BorderStyle="None" BorderWidth="1px" CellPadding="4" DataKeyNames="ArticleID" DataSourceID="SqlDataSource1" ForeColor="Black" GridLines="Vertical" Width="200%" OnSelectedIndexChanged="GridViewListallarticles_SelectedIndexChanged">
                <AlternatingRowStyle BackColor="White" />
                <Columns>
<asp:CommandField ShowDeleteButton="True" ShowEditButton="True" ButtonType="Button" />
<asp:BoundField DataField="ArticleID" HeaderText="ArticleID" InsertVisible="False" ReadOnly="True" SortExpression="ArticleID" />

<asp:TemplateField HeaderText="Title" SortExpression="Title">
<EditItemTemplate><asp:TextBox ID="tbtitle" runat="server" Text='<%# Bind("Title") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidatortitle" Display="None" runat="server" ControlToValidate="tbtitle" Text="*" ErrorMessage="Please Input Article Title" ForeColor="Red" Font-Names="Calibri"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidatortitle" Display="None" runat="server" ControlToValidate="tbtitle" ValidationExpression="^[a-zA-Z''-'\s]{20,50}$" ErrorMessage="Article Title Name Must Contain Only 20-50 Characters" Text="*" Font-Names="Calibri" Font-Size="Small" ForeColor="Red"></asp:RegularExpressionValidator</EditItemTemplate>
<ItemTemplate>
<asp:Label ID="Label1" runat="server" Text='<%# Bind("Title") %>'></asp:Label></ItemTemplate>
</asp:TemplateField>


<asp:TemplateField HeaderText="Body" SortExpression="Body"><EditItemTemplate>
<asp:TextBox ID="tbbody" runat="server" Text='<%# Bind("Body") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidatorbody" Display="None" runat="server" ControlToValidate="tbbody" Text="*" ErrorMessage="Please Input Article Title" ForeColor="Red" Font-Names="Calibri"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidatorbody" Display="None" runat="server" ControlToValidate="tbbody" ValidationExpression="^.{50,500}$" ErrorMessage="Article Body Name Must Contain Only 50-500 Characters" Text="*" Font-Names="Calibri" Font-Size="Small" ForeColor="Red"></asp:RegularExpressionValidator></EditItemTemplate>
<ItemTemplate><asp:Label ID="Label2" runat="server" Text='<%# Bind("Body") %>'></asp:Label>
</ItemTemplate></asp:TemplateField>

<asp:TemplateField HeaderText="Author" SortExpression="Author">
<EditItemTemplate>
<asp:TextBox ID="tbauthor" runat="server" Text='<%# Bind("Author") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidatorauthor" Display="None" runat="server" ControlToValidate="tbauthor" Text="*" ErrorMessage="Please Input Author Name" ForeColor="Red" Font-Names="Calibri"></asp:RequiredFieldValidator>
<asp:RegularExpressionValidator ID="RegularExpressionValidatorauthor" Display="None" runat="server" ControlToValidate="tbauthor" ValidationExpression="^[a-zA-Z''-'\s]{10,50}$" ErrorMessage="Author Name Must Contain Only 1-50 Characters" Text="*" Font-Names="Calibri" Font-Size="Small" ForeColor="Red"></asp:RegularExpressionValidator></EditItemTemplate>
<ItemTemplate> <asp:Label ID="Label3" runat="server" Text='<%# Bind("Author") %>'></asp:Label></ItemTemplate></asp:TemplateField>

<asp:TemplateField HeaderText="Categories" SortExpression="Categories">
<EditItemTemplate>
<asp:TextBox ID="tbcategory" runat="server" Text='<%# Bind("Categories") %>'></asp:TextBox>
<asp:RequiredFieldValidator ID="RequiredFieldValidatorcategory" Display="None" runat="server" ControlToValidate="tbcategory" Text="*" ErrorMessage="Please Input Article Category" ForeColor="Red" Font-Names="Calibri"></asp:RequiredFieldValidator></EditItemTemplate>
<ItemTemplate><asp:Label ID="Label4" runat="server" Text='<%# Bind("Categories") %>'></asp:Label</ItemTemplate></asp:TemplateField>

<asp:BoundField DataField="PublishedOn" HeaderText="PublishedOn" SortExpression="PublishedOn" />
<asp:BoundField DataField="PublishedBy" HeaderText="PublishedBy" SortExpression="PublishedBy" />
<asp:BoundField DataField="UpdatedOn" HeaderText="UpdatedOn" SortExpression="UpdatedOn" />
<asp:BoundField DataField="Updatedby" HeaderText="Updatedby" SortExpression="Updatedby" />
<asp:BoundField DataField="countlikes" HeaderText="countlikes" SortExpression="countlikes" />
<asp:BoundField DataField="SubcriptionId" HeaderText="SubcriptionId" SortExpression="SubcriptionId" />
</Columns>
<FooterStyle BackColor="#CCCC99" />
<HeaderStyle BackColor="#6B696B" Font-Bold="True" ForeColor="White" />
<PagerStyle BackColor="#F7F7DE" ForeColor="Black" HorizontalAlign="Right" />
<RowStyle BackColor="#F7F7DE" />
<SelectedRowStyle BackColor="#CE5D5A" Font-Bold="True" ForeColor="White" />
<SortedAscendingCellStyle BackColor="#FBFBF2" />
<SortedAscendingHeaderStyle BackColor="#848384" />
<SortedDescendingCellStyle BackColor="#EAEAD3" />
<SortedDescendingHeaderStyle BackColor="#575357" />
</asp:GridView></div>
<asp:ValidationSummary ID="ValidationSummary1" runat="server" Font-Names="Calibri" Font-Size="Small" HeaderText="Invalid Input" ShowMessageBox="True" ShowSummary="False" />