Index: /issm/trunk-jpl/src/c/analyses/StressbalanceSIAAnalysis.cpp
===================================================================
--- /issm/trunk-jpl/src/c/analyses/StressbalanceSIAAnalysis.cpp	(revision 19533)
+++ /issm/trunk-jpl/src/c/analyses/StressbalanceSIAAnalysis.cpp	(revision 19534)
@@ -338,5 +338,8 @@
 	Input* thickness_input = element->GetInput(ThicknessEnum);            _assert_(thickness_input);
 	Input* surface_input   = element->GetInput(SurfaceEnum);              _assert_(surface_input);
-	Input* drag_input      = element->GetInput(FrictionCoefficientEnum);  _assert_(drag_input);
+	Input* drag_input      = NULL;
+	if(frictionlaw!=5 && frictionlaw!=1){
+		drag_input = element->GetInput(FrictionCoefficientEnum);  _assert_(drag_input);
+	}
 
 	Gauss* gauss=element->NewGauss();
@@ -348,5 +351,4 @@
 		thickness_input->GetInputValue(&thickness,gauss);
 		surface_input->GetInputValue(&surface,gauss);
-		drag_input->GetInputValue(&drag,gauss);
 		slopex_input->GetInputValue(&slope[0],gauss);
 		slopey_input->GetInputValue(&slope[1],gauss);
@@ -361,4 +363,5 @@
 			case 2:
 				/*Ritz et al. 1996*/
+				drag_input->GetInputValue(&drag,gauss);
 				ub=drag*(rho_ice*gravity*thickness)*(rho_ice*gravity*thickness)*slope[0]/sqrt(slope2);
 				vb=drag*(rho_ice*gravity*thickness)*(rho_ice*gravity*thickness)*slope[1]/sqrt(slope2);
@@ -366,4 +369,5 @@
 			case 3:
 				/*Rutt et al. 2009*/
+				drag_input->GetInputValue(&drag,gauss);
 				ub=-drag*rho_ice*gravity*thickness*slope[0];
 				vb=-drag*rho_ice*gravity*thickness*slope[1];