This command is not available because no document is open.

Question

I am trying to convert ms word to html page.
but i got error as below. can anybody help me to solve this problem.
I have also licence of ms office 2007 in my server.

This command is not available because no document is open. at Microsoft.Office.Interop.Word

Find out all coding which i am using please find below link

qhengineerszone.com/ja.aspx