Try this, id does not actualy delete anything, it demonstrates linking upon confirmation.
The bottom link should work on all browsers, while upper does not work on IE 8.
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<a href="https://www.google.si/" onclick="return confirm('Are you sure you want to delete?')">Delete href</a>
Otherwise your error looks like from PHP.
It has nothing to do with .....
When your PHP will be error free, then you wil still have to look at html page source (and that should look something like my upper code.)
I doubt you can look at PHP generated html source as old pedant suggested, at this stage, coz I asume it is nothin there, due to error.
EDIT: Not PHP man myself, but if you look here: http://php.net/manual/en/language.operators.string.php
all strings are inside "" not inside '' like in your case ..... There might be your problem.