Go here and download and install the AutoDesk DWF Viewer
http://usa.autodesk.com/adsk/servlet/index?id=2404513&siteID=123112
Then when you click on the supplied link
<span style='color:red'>Drawing 1 </span>
<span style='color:red'>Drawing 2 </span>
You'll be able to zoom in and pan about with no loss of Quality. It works
a lot like Adobe Acrobat Reader :-)