title: How do I make my Apache 2 server force a browser to open a file transfer dialogue?
body: <p>How do I make my Apache 2 server force a browser to open a file transfer dialogue if the URL points to a file with a .pln or .psa extension?</p>
  
  <p>I have a simple LAMP server with CentOS 5, Apache 2, MYSQL 5, PHP 5, recently built CentOS 5.2 i386 installation CDs. My web application generates files to be downloaded and imported into a custom application. The file extensions are .psa and .pln. How do I make my server force the browser to open a file transfer dialogue? If I point my browser to a .psa or .pln file on the Apache 2 server, the file's content is displayed in a pop-up window as simple text. I want a file transfer dialogue.</p>
  
  <p>The web-app I am working on is deployed on another web-server and handles the .pln and .psa files as desired.  I cannot compare server configuration files because I do not have administrator access to the working server.</p>
  
  <p>How do I change my server's behavior?  Does this require code changes to my web-app code (such as sending explicit headers)?  If so, why does it work against the other server?  Can code changes be avoided by configuring the server's default behavior?</p>
  
  <p>Any help would be appreciated.</p>