Trying To Insert Checkbox True/false Into Db

Hi there, I've tried googling this (and looking at the many questions on the forum :) but I've not managed to find a decent tutorial / guide that describes a method for using checkboxs to insert true/false flags in a MS SQL db.  The db field i'm setting has type set to "bit", is this correct?  And secondly (its been a long day!) I just cant figure out the code to assign the bit 1 or 0 / true or false. This is what I've got so far but it's not working........Function InsertProduct(ByVal prod_code As String, ByVal prod_name As String, ByVal prod_desc As String, ByVal prod_size As String, ByVal prod_price As String, ByVal prod_category As String, ByVal aspnet As Boolean) As Integer             Dim connectionString As String = "server='server'; user id='sa'; password='msde'; Database='dbLD'"             Dim sqlConnection As System.Data.SqlClient.SqlConnection = New System.Data.SqlClient.SqlConnection(connectionString)                 Dim queryString As String = "INSERT INTO [tbl_LdAllProduct] ([prod_code], [prod_name], [prod_desc], [prod_size], [prod_price], [prod_category],[aspnet]) VALUES (@prod_code, @prod_name, @prod_desc, @prod_size, @prod_price, @prod_category, @aspnet)"             Dim sqlCommand As System.Data.SqlClient.SqlCommand = New System.Data.SqlClient.SqlCommand(queryString, sqlConnection)                 sqlCommand.Parameters.Add("@prod_code", System.Data.SqlDbType.VarChar).Value = prod_code             sqlCommand.Parameters.Add("@prod_name", System.Data.SqlDbType.VarChar).Value = prod_name             sqlCommand.Parameters.Add("@prod_desc", System.Data.SqlDbType.VarChar).Value = prod_desc             sqlCommand.Parameters.Add("@prod_size", System.Data.SqlDbType.VarChar).Value = prod_size             sqlCommand.Parameters.Add("@prod_price", System.Data.SqlDbType.VarChar).Value = prod_price             sqlCommand.Parameters.Add("@prod_category", System.Data.SqlDbType.VarChar).Value = prod_category                 If chkAspnet.Checked = True Then                sqlCommand.Parameters.Add("@aspnet","1")             Else                sqlCommand.Parameters.Add("@aspnet","0")             End If                     Dim rowsAffected As Integer = 0             sqlConnection.Open             Try                 rowsAffected = sqlCommand.ExecuteNonQuery             Finally                 sqlConnection.Close             End Try             Return rowsAffected         End Function             Sub SubmitBtn_Click(sender As Object, e As EventArgs)            If Page.IsValid then                InsertProduct(txtCode.Text, txtName.Text, txtDesc.Text, ddSize.SelectedItem.value, ddPrice.SelectedItem.value, ddCategory.SelectedItem.value, aspnet.value)                Response.Redirect("ListAllProducts.aspx")            End If    End SubAny help would be appreciated or links to tutorials.ThanksBen