Can't set IGES precision

Hi,

I'm getting a complier error when I try to set the precision for writing an IGES file. The line is commented below and it gives the following complier error:

error C2653: 'Interface_Static' : is not a class or namespace name
error C3861: 'SetIVal': identifier not found

Code Snippet:

IGESControl_Controller::Init();
IGESControl_Writer ICW ("MM", 1);

//this line causes the error
if (!Interface_Static::SetIVal("write.precision.mode",-1))

TopoDS_Shape sh;
ICW.WriteAddGeom (K);
//adds shape sh to IGES model
ICW.ComputeModel();
Standard_Boolean OK = ICW.Write ("d:\\opencascade6.3.0\\samples\\standard\\qt\\MyFile.igs");

Can anyone advise me on how to fix this?

P.S. My related includes are:

#include
#include
#include
#include

but maybe I'm missing some others??

Thanks,

Mike.