Populate DataGrid with results based on DropDownList selection

Hi Experts,

I have a page which displays a dropdownlist, followed by a DataGrid with results extracted from a database.  Once the dropdownlist is changed, the results in the datagrid should change to reflect the choice, however, despite my attempts the DropDownList seems to Postback, but not change the results in the DataGrid.

Code is detailed below ... anyone's help would be greatly appreciated.  :)

Sample:  

ASCX Control HTML ....
<table><tr><td><asp:placeholder id="ResultsSpan" runat="server"></asp:placeholder>
<ASP:DATAGRID id="ResultsDataGrid" runat="server" AutoGenerateColumns="True" Width="100%" CssClass="moduleBody" ShowFooter="false" OnPageIndexChanged="myDataGrid_PageChanger" PagerStyle-Mode="NumericPages" PageSize="10" AllowPaging="True" EnableViewState="true" AllowSorting="true" SortCommand="SortGrid">
</ASP:DATAGRID></td></tr></table>

C# Code Behind

public class myDataTest : System.Web.UI.UserControl
      {
            protected System.Web.UI.WebControls.PlaceHolder ResultsSpan;
            protected System.Web.UI.WebControls.DataGrid ResultsDataGrid;
            protected System.Web.UI.WebControls.DropDownList SelectStatus;
            private string status = "Not Selected"

            private void Page_Load(object sender, System.EventArgs e)
            {
                  if(Page.IsPostBack == false)
                  {
                          PopulateStatus();      
                  }
                  BindGrid();
            }

            public void SelectStatus_SelectedIndexChanged(object sender, System.EventArgs e)
            {
                  string status = SelectStatus.SelectedItem.Value;
                  BindGrid();
            }

            public void BindGrid(string inStatus)
            {
                  //get a dataset from component
                  myApplication.ContactDB db = myApplication.ContactDB();
                                                DataSet ds = new DataSet();
                  ds = db.GetResults();

                  DataView view = new DataView(ds.Tables[0]);

                  //Sorting criteria
                  view.Sort = SortField;  if (!SortAscending)  { view.Sort += " DESC";  }

                  ResultsDataGrid.DataSource = view;
                  ResultsDataGrid.DataBind();
            }

            // using ViewState for SortField property
            string SortField
            {       get
                  {
                        object o = ViewState["SortField"];
                        if (o == null) { return String.Empty; }
                        return (string)o;
                  } set
                  {
                        if (value == SortField)
                        {      //if ascending change to descending or vice versa.
                              SortAscending = !SortAscending; }
                        ViewState["SortField"] = value;
                  }
            }

            // using ViewState for SortAscending property
            bool SortAscending
            {
                  get
                  {
                        object o = ViewState["SortAscending"];
                        if (o == null) { return true; } return (bool)o;
                  }
                  set { ViewState["SortAscending"] = value; }
            }

            protected void SortGrid(Object src, DataGridSortCommandEventArgs e)
            {
                  ResultsDataGrid.CurrentPageIndex = 0;
                  SortField = e.SortExpression;    
                  BindGrid();
            }

            protected void myDataGrid_PageChanger(Object src, DataGridPageChangedEventArgs e)
            {
                  ResultsDataGrid.CurrentPageIndex = e.NewPageIndex;
                  BindGrid();
            }

            public DataSet PopulateStatus()
            {
                  DataSet ds = new DataSet();
                  
                  myApplication.ContactDB db = new myApplication.ContactDB();
                  
                  SelectStatus.DataSource = db.GetStatusList();
                  SelectStatus.DataTextField = "STATUS";
                  SelectStatus.DataValueField = "STATUS";
                  SelectStatus.DataBind();
                  return ds;
            }

            #region Web Form Designer generated code
            override protected void OnInit(EventArgs e)
            {
                  //
                  // CODEGEN: This call is required by the ASP.NET Web Form Designer.
                  //
                  InitializeComponent();
                  base.OnInit(e);
            }
            
            private void InitializeComponent()
            {
                  this.SelectStatus.SelectedIndexChanged += new System.EventHandler(this.SelectStatus_SelectedIndexChanged);
                  this.Load += new System.EventHandler(this.Page_Load);

            }
            #endregion
      }
}