I trust that the messages actually give a lot more detail than you've quoted?

Please give the full text of the messages - without that, we can only guess!

You have looked up the messages for any explanations in the Manual, haven't you?

Also, please re-post your code, putting it between 'pre' and '/pre' HTML tags to preserve the layout.
NB: you actually need to type angle brackets < and > where I put the single-quotes