[vtkusers] Intersection?

[Subramanian, S.]

Hi,
 I am  new to vtk and have the following question. 
How do I find the point of intersection of a cube with a line using vtk?
Can I use vtkclippolydata? 
I tried the following but it gives an error that vtkline is not part of
ImplicitFunction.

	vtkLine *line = vtkLine::New();
		line->GetPointIds()->SetId(0,0);
		line->GetPointIds()->SetId(1,1);
		line->GetPoints()->SetPoint(0,point1);
		line->GetPoints()->SetPoint(1,point2);

	vtkClipPolyData *clipper = vtkClipPolyData::New();
		clipper->SetInput(cube->GetOutput());
		clipper->SetClipFunction(line);
		clipper->GenerateClippedOutputOn();
		clipper->SetValue(0.5);
I tried introducing 
vtkImplicitDataSet *dataset;
but line is not compatible with that too.
I am missing something silly here,
Can you help me?
thanks in advance,
Sriram