var arItems = 
[
  ['Material Safety Data Sheet',
    [
	  ['Belgard and paver MSDS', 'Belgard and paver MSDS.pdf'] 
	]
  ]

]

section = getParameter(self.document.location.href, 'section');
if (isNaN(section) || (section=='') || (section<0) || (section>arItems.length))
  section = 0;