I'm trying a simple update

Code:
sub Opslaan_Click (s as object , e as eventargs)

			dim CON as odbcconnection
			dim CMD as odbccommand
			dim DTR as odbcdatareader
			dim STR_INSERT, STR_UPDATE as string
			dim ID_type, ID_stock, ID_leverancier as integer			
						
			CON = new odbcconnection("DSN=STOCK")
						
			CON.open
			STR_INSERT = "INSERT INTO producten (pro_type, pro_productnaam, pro_product, pro_producent, pro_leverancier, pro_stockeerplaats, pro_pcsunit, pro_size, pro_weight, pro_minimum, pro_opmerking) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)" 			
			STR_UPDATE = "UPDATE Producten SET pro_type = ?, pro_productnaam = ?, pro_product = ?, pro_producent = ?, pro_leverancier = ?, pro_stockeerplaats = ?, pro_pcsunit = ?, pro_size = ?, Pro_weight = ?, pro_minimum = ?, pro_opmerking = ? WHERE pro_id = ?"
			
			response.write(id_product)
			
			if request.querystring("id") = ""
				CMD = New odbcCommand(STR_INSERT, CON)
			else
				CMD = New odbcCommand(STR_UPDATE, CON)
			end if

			CMD.parameters.add ("@type", ID_type)			
			CMD.parameters.add ("@productnaam", "HELLOOOOOOOOOw") 'this field DOES update -> hardcoded
			CMD.parameters.add ("@product", txtproduct.text)
			CMD.parameters.add ("@producent", txtproducent.text)
			CMD.parameters.add ("@leverancier", ID_leverancier)
			CMD.parameters.add ("@stockeerplaats", ID_stock)
			CMD.parameters.add ("@pcs", txtpcsunit.text)
			CMD.parameters.add ("@weight", txtweight.text)
			CMD.parameters.add ("@size", txtsize.text)
			CMD.parameters.add ("@minimum", txtminimum.text)
			CMD.parameters.add ("@opmerking", txtopmerking.text)					 
						
			if not request.querystring("id") = ""
				CMD.parameters.add ("@id", id_product)					 
			end if
							
			CMD.ExecuteNonQuery()
			CON.close
			
		end sub

there are no errors, but the fields in my database are not updated...except for the one hardcoded "HELLOOOOOOOOOw"

Can i check the SQL-statement that is generated by the program somewhere?

I must be missing something...