Display Word and PDF Documents directly in browser using ASP.Net

Hi,

please look at code below

 <a href="untitled.GIF">untitled</a>
    <a href="aaa.txt">aaa</a>
    <a href="DaryaSoft_FaxList_pdf.pdf">pdf</a>
    <a href="4663750304151.swf">swf</a>

when I click on gif and txt file links I can see Image and content of txt file in page and their address in address bar but by clicking on swf and png files link download dialog box appear?

what can I do? someone sain I need to remove this type of files from htaccess and I searched

and found the Equivalent of htaccess is authorization section of web.config but I don't know

what can I do there?

I need when click link I can see file and it's address in address bar.