Index: ../trunk-jpl/src/m/classes/flowequation.m
===================================================================
--- ../trunk-jpl/src/m/classes/flowequation.m	(revision 19068)
+++ ../trunk-jpl/src/m/classes/flowequation.m	(revision 19069)
@@ -157,6 +157,9 @@
 			if strcmp(domaintype(md.mesh),'2Dhorizontal')
 				md = checkfield(md,'fieldname','flowequation.vertex_equation','size',[md.mesh.numberofvertices 1],'values',[1:2]);
 				md = checkfield(md,'fieldname','flowequation.element_equation','size',[md.mesh.numberofelements 1],'values',[1:2]);
+			elseif strcmp(domaintype(md.mesh),'3Dsurface')
+				md = checkfield(md,'fieldname','flowequation.vertex_equation','size',[md.mesh.numberofvertices 1],'values',[1:2]);
+				md = checkfield(md,'fieldname','flowequation.element_equation','size',[md.mesh.numberofelements 1],'values',[1:2]);
 			elseif strcmp(domaintype(md.mesh),'2Dvertical')
 				md = checkfield(md,'fieldname','flowequation.vertex_equation','size',[md.mesh.numberofvertices 1],'values',[2,4,5]);
 				md = checkfield(md,'fieldname','flowequation.element_equation','size',[md.mesh.numberofelements 1],'values',[2,4,5]);
