I have a table which contains 4 Columns. What I want to be able to do is to filter this datatable according to the selection of a multiple DropDownList. 

How can I delete the rows which don't contain the selection?? I've used SQL to populate the datatable but I don't want to call SQL to filter the datatable?

Heres my code on how I add the datatable and populate the dropdownlists

```
private DataTable LoadDataTable()
{
    //conn.Open();
    DataTable dt = new DataTable();
    SqlDataAdapter adapter = new SqlDataAdapter("SELECT * FROM DataTest", conn);

    adapter.Fill(dt);
    conn.Close();  
    return dt;                                          
}

public void PopulateDDL()
{
    SqlCommand cmd = new SqlCommand("SELECT DISTINCT Column1 FROM DataTest", conn);
    cmd.Connection.Open();

    SqlDataReader ddlValues;
    ddlValues = cmd.ExecuteReader();

    DropDownList1.DataSource = ddlValues;
    DropDownList1.DataValueField = "Column1";
    DropDownList1.DataTextField = "Column1";
    DropDownList1.DataBind();

    cmd.Connection.Close();            
}

```

Anyway I could go about it?