Mai Nur , "it however fails every time I click it" Please do not trigger my imagination, be more precise.

In general, what I do is just record the call in your browser with network tracing (open debug tools of browser (F12); go to network tab). Click on the button and see how the call looks in the browser: Check headers, etc.

However in this particular case you might have a look to web_url help page. You might note that here is no "Text=" argument, but an "URL=" argument.

P.S.

I've made that kind of mistakes my self as well and most of time a quick code review of a colleague makes things clear. The more experienced you are the more likely you will hit this kind of errors. Experience make you read code at structural level and not at word-level. A very good book about this is "The programmers brain" I think every one that guides colleagues and like to have a better understanding on how to learn efficiently should read this book.

thank you JHF Remmelzwaal  for the reference and for your response, much appreciated