Well, there's an 'is()' :)
http://www.digitalmars.com/d/1.0/expression.html#IsExpression

In my case, I had the implibs stored in dmd\lib directory... so I don...

...added Point 9 to the installation page
http://www.dsource.org/projects/dwt/wiki/Installation

...speed to build dwt.lib

I'm using DSSS to build dwt.lib, one hour...

Great, thanks a lot. It works now.

I've had this error before too... These functions are in User32.lib and Kernel32...

Yup. Still the same error

...case. Did you also apply -full while building the dwt lib?

dsss build dwt -full

...m using dsss 0.75, dmd 1.025, tango rev 3317 and dwt rev 172.

If building with dsss, please try to add -full to the commandline.