Hi Aderson,
thanks for that, I looked into it - and the penny dropped that I cannot use form tags with DNN.
Adding to the complexity multiple paypal buttons require a separate form tag for each button because each button has a named input element with a paypal button ID, if this is duplicated with multiple buttons, then only the last named input id value is used - and you always get the same product when clicking the button to go to PayPal.
I solved it finally, by adding an IFrame for each button, each Iframe points to a htm file I have created that accepts URL parameter 'button_id', so in the DNN module I have an entry like this for each button:
<iframe height="20" marginheight="0" src="/PayPalButton.htm?button_id=NSX9999KXPE" frameborder="0" width="100" marginwidth="0" scrolling="no"></iframe>
The page PayPalButton.htm contains javascript extract get button id from the url and create the button code.
I can upload and share the html file here but I am note sure how to do that?
Anyway it works!!!!
Wahoo :)
Thanks for your guidance
Richard