GridView and AccessDataSource updating the database doesnt work - asp.net

Question

AccessDataSource doesnt pick up edited data from GridView and it doesnt save it to database.
Can someone tell what am I doing wrong here? Updating the database doesnt work.
<asp:AccessDataSource ID="AccessDataSource1" runat="server" DataFile="~/App_Data/baza.mdb"
SelectCommand="SELECT * FROM [users]"
DeleteCommand="DELETE FROM users WHERE (username = ?)"
InsertCommand="INSERT INTO users(username, [password], isAdmin) VALUES (?, ?, ?)"
OldValuesParameterFormatString="original_{0}"
UpdateCommand="UPDATE [users] SET [username] = ?, [password] = ?, [isAdmin] = ? WHERE ([username] = ?)">
<DeleteParameters>
<asp:Parameter DbType="String" Name="username" />
</DeleteParameters>
<InsertParameters>
<asp:Parameter DbType="String" Name="username" />
<asp:Parameter DbType="String" Name="password" />
<asp:Parameter DbType="String" Name="isAdmin" />
</InsertParameters>
<UpdateParameters>
<asp:Parameter DbType="String" Name="username" />
<asp:Parameter DbType="String" Name="password" />
<asp:Parameter DbType="String" Name="isAdmin" />
<asp:Parameter DbType="String" Name="original_username" />
</UpdateParameters>
</asp:AccessDataSource>
<asp:GridView ID="GridView1" runat="server" AutoGenerateColumns="False" DataKeyNames="username" DataSourceID="AccessDataSource1" AllowPaging="True" CellPadding="10" ForeColor="#333333" GridLines="None" AllowSorting="True" AutoGenerateDeleteButton="True" AutoGenerateEditButton="True">
<AlternatingRowStyle BackColor="White" ForeColor="#284775"></AlternatingRowStyle>
<Columns>
<asp:BoundField DataField="username" HeaderText="username" SortExpression="username" ItemStyle-HorizontalAlign="Center"></asp:BoundField>
<asp:BoundField DataField="password" HeaderText="password" SortExpression="password"></asp:BoundField>
<asp:BoundField DataField="isAdmin" HeaderText="isAdmin" SortExpression="isAdmin"></asp:BoundField>
</Columns>
<EditRowStyle BackColor="#999999"></EditRowStyle>
<FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White"></FooterStyle>
<HeaderStyle Font-Bold="True" ForeColor="#cecece"></HeaderStyle>
<PagerStyle HorizontalAlign="Center" BackColor="#284775" ForeColor="#284775"></PagerStyle>
<RowStyle BackColor="#f8f8f9" ForeColor="#fff"></RowStyle>
<SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333"></SelectedRowStyle>
</asp:GridView>