help on ASP - database connection

hi, i'm new on ASP. I'm using connection string to connect my database from a web server. I can attract the data I want from the database, but I can't write data or edit the database.

Any idea why?  below is the delete coding.

Set conn = server.createobject("adodb.connection")conn.Provider="Microsoft.Jet.OLEDB.4.0"
conn.Open(Server.Mappath("Mydata.mdb"))
SQL = "Delete * From " & which & " Where ID =" & uid
conn.Execute(SQL)
Conn.Close