Problem with C# and SQL filtering asp.net 2.0 GridView in session

Hi
 
I have a bad problem, I use session to filter the database.
 
I wish to use the sql statment when upload the grid: 
SELECT [CompanyName], [ContactName], [Country], [City], [CustomerID], [PostalCode] FROM [Customers] order by CompanyName
 
And I wish to use the sgl statment with filtering 
 
SELECT [CompanyName], [ContactName], [Country], [City], [CustomerID], [PostalCode] FROM [Customers] WHERE [CompanyName] LIKE    '%" + CompanyName.Text + "%'  AND [Country] = '" + Country.Text + "' order by contactname"
 
MY PROBLEM IS: that I get an where clause error because of that the string use the session from the postback, How do a soluation do about this ?
 
My codefil
 
using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
 
public partial class _Default : System.Web.UI.Page {
protected void Page_Load(object sender, EventArgs e)
{ 
 
 
if (CompanyName.Text == "" && ContactName.Text == "" && PostalCode.Text == "") 
{
 
SqlDataSource1.SelectCommand = "SELECT [CompanyName], [ContactName], [Country], [City], [CustomerID], [PostalCode] FROM [Customers]";
 
}
if (!IsPostBack) 
{
 
Session["SQLSelect"] = SqlDataSource1.SelectCommand;
}if (Session["SQLWhere"] != null) 
{
 
SqlDataSource1.SelectCommand = String.Format("{0} {1}", Session["SQLSelect"], Session["SQLWhere"]); 
}
 
 
 
 
 
}
 
protected void Button1_Click(object sender, EventArgs e) 
{
 
string strWhere = " WHERE [CompanyName] LIKE '%" + CompanyName.Text + "%' order by contactname"; 
if (ContactName.Text.Length > 0)
 
strWhere += " AND [ContactName] LIKE '%" + ContactName.Text + "%' order by contactname"; 
if (PostalCode.Text.Length > 0)
 
strWhere += " AND [PostalCode] LIKE '%" + PostalCode.Text + "%' order by contactname"; 
if (City.Text.Length > 0)
 
strWhere += " AND [City] LIKE 'CustID=%" + City.Text + "%' order by contactname"; 
if (Country.Text.Length > 0)
 
strWhere += " AND [Country] = '" + Country.Text + "' order by contactname"; 
 
 
Session["SQLWhere"] = strWhere;SqlDataSource1.SelectCommand = String.Format("{0} {1}", Session["SQLSelect"], Session["SQLWhere"]); 
}
 
 
 
}