image file validating using jquery in asp.net

<script src="http://ajax.googleapis.com/ajax/libs/jqueryui/1/jquery-ui.min.js" type="text/javascript"></script>
<script src="htp://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js" type="text/javascript"></script>
<script type="text/javascript">
    $(function () {
        $('#<%=FileUpload1.ClientID %>').change(function () {
            var ValidFileExtension = ['jpg', 'JPG', 'jpeg', 'JPEG', 'png', 'PNG', 'gif', 'GIF', 'bmp', 'BMP'];
        if ($.inArray($(this).val().split('.').pop().toLowerCase(), ValidFileExtension) == -1) {
            alert("Sorry !!! Allowed image formats are '.jpeg','.jpg', '.png', '.gif', '.bmp'");
        }
    });
});
</script>


    <table>
                <tr>
                    <td colspan="2"><asp:FileUpload ID="FileUpload1" runat="server" /></td>                  
                </tr>
                <tr>
                    <td><asp:Button ID="btnUpload" runat="server" Text="Upload" OnClick="btnUpload_Click" /></td>
                    <td>
                        <asp:Label ID="lblStatus" runat="server" Text=""></asp:Label></td>
                </tr>            
            </table>  


protected void btnUpload_Click(object sender, EventArgs e)
    {
        string filePath = string.Empty;
        try
        {
            filePath = (Server.MapPath("Images/") + Guid.NewGuid() + FileUpload1.FileName);
            FileUpload1.SaveAs(filePath);
            lblStatus.Text = "Image uploaded successfully";
            lblStatus.ForeColor = System.Drawing.Color.Green;
        }
        catch (Exception ex)
        {
            lblStatus.Text = "Image couldn't be uploaded";
            lblStatus.ForeColor = System.Drawing.Color.Red;        
        }
        finally
        {
            filePath = string.Empty;
        }    
    }