How do i put html codes inside my div?

Question

what i want to do is like this:
http://www.w3schools.com/html/tryit.asp?filename=tryhtml_iframe_target

but the html that will be send on iframe will be the HTMLBody of an msg file.

 

the html code is coming from .msg file

MailItem item = (MailItem)app.CreateItemFromTemplate(@"C:\Users\elayronj\Desktop\Sample\sample.msg", 
Type.Missing);   

string body = item.HTMLBody;  

my problem is, when i get item.HTMLBody and display on the div/iframe, 
its replacing the above html tags.