Forms Data Controls :: GridView Does Not Show Data?

ASP code

<asp:RadioButtonList ID ="radio1" AutoPostBack="true" runat="server"
onselectedindexchanged="radio1_SelectedIndexChanged">
<asp:ListItem Text = "Department"></asp:ListItem>
<asp:ListItem Text = "Employee"></asp:ListItem>
<asp:ListItem Text ="Operations"></asp:ListItem>
<asp:ListItem Text="Workcenter"></asp:ListItem>
</asp:RadioButtonList>
<br />
<br />
<asp:GridView ID="GridView1" runat="server" AutoGenerateDeleteButton="True"
AutoGenerateEditButton="True" DataSourceID="LinqDataSource1"
ShowHeaderWhenEmpty="True">
</asp:GridView>

c sharp code

public partial class DataEntry : System.Web.UI.Page
{
TrackingDataContext tracking = new TrackingDataContext();
protected void Page_Load(object sender, EventArgs e)
{
}
protected void radio1_SelectedIndexChanged(object sender, EventArgs e)
{
if (radio1.SelectedValue.Equals("Department"))
{
GridView1.DataSource = tracking.GetDeptartmentNames();
if (GridView1.Rows.Count > 0)
{
GridView1.DataBind();
}
}
}
}
GetDeptartmentNames() is the name of the stored proc, when i execute the stored proc inside the database

i see results but gridview is empty any reson