Forms Data Controls :: Grid View Is Unable To Return The Values That Are Present In

I have a grid view and I added edit and Save buttons to it. When I click on edit I am able to edit the data but when I click on save I amgetting the data before edit.

Please see my code below.

Eg: I have start date as 2005-10-10 12:00 AM so After I click On edit it is letting me to edit, So If I edit the start date to 2010-10-10 12:00 PM and click on the save button I am stil getting the old start date. which is 2005-10-10 12:00 AM instead of 2010-10-10 12:00 PM

<asp:GridView ID="gvPosHistory" runat="server" AutoGenerateColumns="False" AllowPaging="True"
AllowSorting="true" Width="650px" PageSize="20" CssClass="Gridview" Visible="false"

OnRowCommand="gvPosHistory_RowCommand"
OnRowDataBound="gvPosHistory_RowDataBound"
OnRowEditing="gvPosHistory_RowEditing"
OnRowUpdating="gvPosHistory_RowUpdating"
onrowcancelingedit="gvPosHistory_RowCancelingEdit" >
<Columns>
<asp:TemplateField HeaderText="Start Date" SortExpression="startDate">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblstartdate" runat="server" text='<%# Eval("StartDate")%>'></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtStartDate" runat="server" Text='<%# Bind("StartDate")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="End Date" SortExpression="endDate">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblenddate" runat="server" text='<%# Eval("EndDate")%>' ></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtEndDate" runat="server" Text='<%# Bind("EndDate")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Functional Job Title" SortExpression="JobTitle">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblFunctjobTitle" runat="server" text='<%# Eval("FunctionalJobTitle")%>' ></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtFuncJobTitle" runat="server" text='<%# Bind("FunctionalJobTitle")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Department" SortExpression="Department">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblDepartment" runat="server" text='<%# Eval("DeptName")%>'></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtDeptName" runat="server" Text='<%# Bind("DeptName")%>'></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Supervisor" SortExpression="Supervisor">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblSupervisor" runat="server" text='<%# Eval("Supervisor")%>'></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtSupervisor" runat="server" Text='<%# Bind("Supervisor")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Bargaining Unit" SortExpression="bargainingunit">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblbargainingunit" runat="server" text='<%# Eval("BargainingUnit")%>' ></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtBargainingUnit" runat="server" text='<%# Bind("BargainingUnit")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="UCP Level" SortExpression="UCPlevel">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center"
VerticalAlign="Top" />
<ItemStyle Wrap="False" HorizontalAlign="Left" />
<ItemTemplate>
<asp:Label ID="lblUCPlevel" runat="server" text='<%# Eval("UCPLevel")%>' ></asp:Label>
</ItemTemplate>
<EditItemTemplate >
<asp:TextBox ID="txtUcpLevel" runat="server" Text='<%#Bind("UCPLevel")%>' ></asp:TextBox>
</EditItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Edit" SortExpression="Edit">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center" VerticalAlign="Top" />
<ItemStyle Wrap="True" HorizontalAlign="Left" />
<ItemTemplate>
<asp:LinkButton ID="LBPosHistoryEdit" Text="Edit" runat="server" CommandName="Edit" ></asp:LinkButton>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Save" SortExpression="Save">
<HeaderStyle Wrap="False" Font-Bold="True" HorizontalAlign="Center" VerticalAlign="Top" />
<ItemStyle Wrap="True" HorizontalAlign="Left" />
<EditItemTemplate>
<asp:LinkButton ID="LBPosHistorySave" Text="Save" runat="server" CommandName="SavePosHistory" CommandArgument='<%# Eval("UCPLevel")%>' ></asp:LinkButton>
</EditItemTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
.aspx.cs
protected void gvPosHistory_RowCommand(object source, GridViewCommandEventArgs e)
{
if (e.CommandName == "SavePosHistory")
{
string arg = Convert.ToString(e.CommandArgument);
System.Web.UI.WebControls.LinkButton btnPosHistory = e.CommandSource as System.Web.UI.WebControls.LinkButton;
GridViewRow row = btnPosHistory.NamingContainer as GridViewRow;
TextBox tSdate = row.FindControl("txtStartDate") as TextBox;
TextBox tEdate = row.FindControl("txtEndDate") as TextBox;
TextBox tFuncJobTitle = row.FindControl("txtFuncJobTitle") as TextBox;
TextBox tDeptName = row.FindControl("txtDeptName") as TextBox;
TextBox tSupervisor = row.FindControl("txtSupervisor") as TextBox;
TextBox tBargainingUnit = row.FindControl("txtBargainingUnit") as TextBox;
TextBox tUCPLevel = row.FindControl("txtUcpLevel") as TextBox;
}
}