opening pdf's in xhtml

i have an <ol> where each <li> item is a pdf.

<ol>
<li class="dark_blue_underline">Full Course Description PDF </li>
<li class="dark_blue_underline">Course/Exam Schedule PDF</li>
<li class="dark_blue_underline">PDF Registration form </li>
</ol>

how would i code this to open <li> as a pdf'? i've googled this but have had no luck.

thanks.

Unless I'm missing something or you aren't telling us something why don't you just use links?
<ol>
<li class="dark_blue_underline"><a href="urltopdft.pdf">Full Course Description PDF</a></li>
<li class="dark_blue_underline"><a href="urltopdft.pdf">Course/Exam Schedule PDF</a></li>
<li class="dark_blue_underline"><a href="urltopdft.pdf">PDF Registration form</a></li>
</ol>

thank you. i'm working on a re-code and had never worked with pdf's. your help is greatly appreciated.