vs2008 won't let me Imports System.Deployment.Applications

I am Using Visual Studio 2008 sp1 for a WPF application with Visual Basic. I am trying to use the line "Imports System.Deployment.Application" so I can use ApplicationDeployment to create a button to manual check and install updates to my application. However, I get a message that "Application is not a member of deployment". I have constantly researched this and I can't figure out why this isn't working especially considering I 开发者_C百科am using common methods to create a button to check for and install updates. Obviously I am missing something. The only member System.Deployment is "Internal". How do I get the "Application" member to show up? Thank you much!

add a reference to system.deployment