I use #if (DEBUG) to compile different code on different occasion in VS2008.

that works just fine.

But when I move my source and open it with VWD2008.

No matter what compile mode I choose. They compile just the same.

Why is this happening? VWD do not support this feature?

Which type of project you are using?

WebSite Project or Webapplication project?

It was WebApplication in VS2008, and I open that same .sln with VWD 2008 SP1.

I think it is still a WebApplication in VWD.

I didn't see any issue in webapplication project.although there is some thing which can be improve of website project for debug and release mode.[you can't set release mode for website project from configuration manager]

Well, I change my webapplication mode like this.

In the solution manager window. right-click on my project and select property.

Then choose the build tab. There is a configuration drop down list.

I switch between RELEASE and DEBUG there.

Is that correct?