public void RotateInPlace()
		{
			UIDocument uidoc = this.ActiveUIDocument;
			Document doc = uidoc.Document;
			
			 ICollection<ElementId> selectedElementsId = uidoc.Selection.GetElementIds();

			using (Transaction t = new Transaction(doc, "Rotate")){
				t.Start();
				
				foreach (ElementId eid in selectedElementsId) {
					TextElement e = doc.GetElement(eid) as TextElement;
					//XYZ center = e.get_BoundingBox(doc.ActiveView).Max - e.get_BoundingBox(doc.ActiveView).Min;
          
					XYZ baseVector = e.BaseDirection;
					XYZ upVector = e.UpDirection;
					XYZ center = e.Coord + new XYZ(0,0,e.Width*100/2) - upVector.Normalize()*e.Height*100/2; //100 is the view scale
					
					XYZ sec = center + 3 * upVector.Normalize();
					
					//doc.Create.NewDetailCurve(doc.ActiveView, Line.CreateBound(center,sec)); 

					XYZ normalVector = baseVector.CrossProduct(upVector);
					Line axis = Line.CreateUnbound(center, normalVector);

					ElementTransformUtils.RotateElement(doc, eid, axis, Math.PI);
				}
				
				t.Commit();
			       	
			       	
			       }
		}