Must declare the scalar variable "@Product_ID".

hi friends.....
i'm using the following code to save an image to SQLSERVER2005using asp.net.
i got the error message Must declare the scalar variable "@Product_ID". while running the code
.
please help me..
its urgent



cn = New System.Data.OleDb.OleDbConnection(" Provider=SQLOLEDB;SERVER=SERVER\SQLEXPRESS;UID=sa; PASSWORD=kadavan2486;DATABASE=Hard1;Persist Security Info=True;")
cn.Open()
cm.Connection = cn
cm.Parameters.Clear()
cm.Parameters.Add("@Product_ID", OleDbType.BigInt, 4)
cm.Parameters.Add("@Img", OleDbType.VarBinary, img.Length)
cm.Parameters("@Product_ID").Value = 1
cm.Parameters("@Img").Value = img

cm.CommandText = "insert into Product_Small_Image(Product_ID,Img) values(@Product_ID ,@Img)"
cm.ExecuteNonQuery()
cn.Close()

iquad