Cannot use Microsoft.Office.Interop.Visio.dll

[Pradeep]

I have added a reference to "Microsoft.Office.Interop.Visio.dll" in my
project. I am unable to use it in the using statement as shown below:
using Visio = Microsoft.Office.Interop.Visio;

Help me to know any prerequisites for the above statement to work.

 

[Al Edlund]

perhaps a little more information, how about what are you programming with,
which version of visio, how is 'visio' defined?
a couple of the basics
al