Display data in web page based on DropDownList value

Hi makenzi.exc,

Database

--EXEC Vegetables_GetVegetablesDetailsByPrice 90
CREATE PROCEDURE [Vegetables_GetVegetablesDetailsByPrice]
    @PricePerKg INT	
AS
BEGIN	
    SET NOCOUNT ON;	
	IF (@PricePerKg > 10 AND @PricePerKg < 40)
	BEGIN
		SELECT [ID]
			  ,[Name]
			  ,[PricePerKg]
			  ,[Quantity] 
		FROM [Vegetables] 
		WHERE [PricePerKg] BETWEEN 10 AND 40	
	END	
	IF (@PricePerKg > 41 AND @PricePerKg < 70)
	BEGIN
		SELECT [ID]
			  ,[Name]
			  ,[PricePerKg]
			  ,[Quantity] 
		FROM [Vegetables]  
		WHERE [PricePerKg] BETWEEN 41 AND 70	
	END	
	ELSE
	BEGIN
		SELECT [ID]
			  ,[Name]
			  ,[PricePerKg]
			  ,[Quantity] 
		FROM   [Vegetables] 
	END
END

HTML

<asp:DropDownList ID="ddlPricePerKg" runat="server">
    <asp:ListItem Text="Please Select" Value="0"></asp:ListItem>
    <asp:ListItem Text="10" Value="10"></asp:ListItem>
    <asp:ListItem Text="20" Value="20"></asp:ListItem>
    <asp:ListItem Text="30" Value="30"></asp:ListItem>
    <asp:ListItem Text="40" Value="40"></asp:ListItem>
    <asp:ListItem Text="50" Value="50"></asp:ListItem>
    <asp:ListItem Text="60" Value="60"></asp:ListItem>
    <asp:ListItem Text="70" Value="70"></asp:ListItem>
    <asp:ListItem Text="80" Value="80"></asp:ListItem>
    <asp:ListItem Text="90" Value="90"></asp:ListItem>
    <asp:ListItem Text="100" Value="100"></asp:ListItem>
</asp:DropDownList>
<asp:Button Text="Submit" runat="server" OnClick="OnSubmit" />
<hr />
<asp:GridView ID="gvVegetables" runat="server" AutoGenerateColumns="false">
    <Columns>
        <asp:BoundField DataField="ID" HeaderText="Id" />
        <asp:BoundField DataField="Name" HeaderText="Name" />
        <asp:BoundField DataField="PricePerKg" HeaderText="PricePerKg" />
        <asp:BoundField DataField="Quantity" HeaderText="Quantity" />
    </Columns>
</asp:GridView>

Namespace

using System;
using System.Configuration;
using System.Data;
using System.Data.SqlClient;

Code

#region Events

protected void Page_Load(object sender, EventArgs e)
{
    if (!this.IsPostBack)
    {
        this.BindGrid();
    }
}

protected void OnSubmit(Object sender, EventArgs e)
{
    this.BindGrid();
}

#endregion

#region Private Methods

/// <summary>
/// populate GridView
/// </summary>
private void BindGrid()
{
    int price = int.Parse(ddlPricePerKg.SelectedValue);
    string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
    using (SqlConnection sqlConnection = new SqlConnection(constr))
    {
        using (SqlCommand sqlCommand = new SqlCommand("Vegetables_GetVegetablesDetailsByPrice", sqlConnection))
        {
            sqlCommand.CommandType = CommandType.StoredProcedure;
            sqlCommand.Parameters.AddWithValue("@PricePerKg", price);
            using (SqlDataAdapter sqlDataAdapter = new SqlDataAdapter(sqlCommand))
            {
                using (DataTable dtVegetables = new DataTable())
                {
                    sqlDataAdapter.Fill(dtVegetables);
                    gvVegetables.DataSource = dtVegetables;
                    gvVegetables.DataBind();
                }
            }
        }
    }
}
#endregion