Errors when I pass dompdf a value from a form (if I remove the ? it works)

[eits]

Hi,

 

I'm using the dompdf class for creating pdfs from a php page. The php page gets some dynamic data from a database depending on what the id is at the end of the page. (e.g. pdf.php?id=1). However, when I try to do this I get the following error:

Warning: DOMXPath::query() [domxpath.query]: Invalid expression in D:\Websites\pdf\include\stylesheet.cls.php on line 573

Warning: DOMXPath::query() [domxpath.query]: Invalid expression in D:\Websites\pdf\include\stylesheet.cls.php on line 573

Warning: Invalid argument supplied for foreach() in D:\Websites\pdf\include\stylesheet.cls.php on line 575

 

However if I remove the variable at the end it makes a PDF, just not with the data that I require. I have had this working before but just cant for the life of me work out why this isn't happening, has anybody got any ideas?

 

Thanks