ASP.NET

function getKeyCode (e_) {
  return parseInt(e_ ? e_.which : window.event.keyCode);
}
function srcEl(e_) {
  if (window.event)
    return window.event.srcElement;
  else
    return (e_ ? e_.target : null);
}
function onKeyUp(e) {
  var textbox = srcEl(e),
        keyCode = getKeyCode(e);

  var text = textbox.value;
    ....
    fill list box based on "text" string
    ....
}

textbox.onkeyup = onKeyUp;

Public Shared Sub GetSort(ByVal dgGrid As System.Web.UI.WebControls.DataGrid, ByVal ds As System.Data.DataTable, ByVal sortExpr As String) <br />
 Dim dv As DataView = New DataView(ds) <br />
 Dim i As Integer = 0 <br />
 While i < dgGrid.Columns.Count <br />
   If dgGrid.Columns(i).HeaderText.Trim.Length > 0 AndAlso dgGrid.Columns(i).Visible = True Then <br />
     Dim index As Integer = dgGrid.Columns(i).HeaderText.IndexOf("<img") <br />
     If dgGrid.Columns(i).SortExpression = sortExpr AndAlso dgGrid.Columns(i).SortExpression.Length > 0 Then <br />
       If index >= 0 Then <br />
         Dim index1 As Integer = dgGrid.Columns(i).HeaderText.IndexOf("bar_down.gif") <br />
         If index1 >= 0 Then <br />
           dgGrid.Columns(i).HeaderText = dgGrid.Columns(i).HeaderText.Substring(0, index) <br />
           dgGrid.Columns(i).HeaderText += "<img src=../Images/bar_up.gif height=13 width=13 border=0>" <br />
           dv.Sort = sortExpr + " ASC " <br />
         Else <br />
           dgGrid.Columns(i).HeaderText = dgGrid.Columns(i).HeaderText.Substring(0, index) <br />
           dgGrid.Columns(i).HeaderText += "<img src=../Images/bar_down.gif height=13 width=13 border=0>" <br />
           dv.Sort = sortExpr + " DESC" <br />
         End If <br />
       Else <br />
         dgGrid.Columns(i).HeaderText += "<img src=../Images/bar_up.gif height=13 width=13 border=0>" <br />
         dv.Sort = sortExpr + " ASC" <br />
       End If <br />
     Else <br />
       If index >= 0 Then <br />
         dgGrid.Columns(i).HeaderText = dgGrid.Columns(i).HeaderText.Substring(0, index) <br />
       End If <br />
     End If <br />
   End If <br />
   System.Math.Min(System.Threading.Interlocked.Increment(i),i-1) <br />
 End While <br />
 dgGrid.DataSource = dv <br />
 dgGrid.DataBind <br />
End Sub