If you’ve ever wondered how to search an XML file, like you would a regular database, this sample is for you. We start with an XML file called ‘cars.xml’. The rest, though, is code, not history 
You can download the xml file here.
<%@ Import Namespace="System.Data" %>
<script language="VB" Runat="server">
Sub Page_Load(Source as Object, E as EventArgs)
if not Page.IsPostBack then
Dim ds as DataSet = new DataSet()
ds.ReadXml(Server.MapPath("/data/cars.xml"))
ddlPrice.DataSource=ds
ddlPrice.DataTextField="Price"
ddlPrice.DataBind
end if
End Sub
Sub GetCar(Source as Object, E as EventArgs)
Dim dsProducts as DataSet = new DataSet()
dsProducts.ReadXml(Server.MapPath("/data/cars.xml"))
Dim dv as DataView = new DataView(dsProducts.Tables("Products"))
dv.Sort = "Price"
Dim rowIndex as integer = dv.Find(ddlPrice.SelectedItem.Text)
Dim Price, Vehicle as String
if (rowIndex = -1) Then
Response.Write("Car not found")
else
ph1.visible="True"
Price = dv(rowIndex)("Price").ToString()
lblPrice.text = "Price: " + FormatCurrency(Price) + "<br>"
Vehicle = dv(rowIndex)("Vehicle").ToString()
lblCar.text="Vehicle : " + Vehicle
End If
End Sub
</script>
<html>
<head>
<meta name="GENERATOR" Content="ASP Express 3.1">
<title>Searching an XML File</title>
</head>
<body>
<form id="form1" Runat="server">
<asp:DropDownList id="ddlPrice" Runat="server"/>
<asp:Button id="button1"
Text="Get Car"
onclick="GetCar"
Runat="server" /><br>
<asp:placeholder ID="ph1" Visible="False" Runat="server">
<asp:Label ID="lblCar" Runat="server" /> --
<asp:Label ID="lblPrice" Runat="server" /><br>
</asp:placeholder>
</form>
</body>
</html>