diff --git a/samples/advanced/fileread/amg_cf_sample.f90 b/samples/advanced/fileread/amg_cf_sample.f90
index 26544d6e..32b7a6c4 100644
--- a/samples/advanced/fileread/amg_cf_sample.f90
+++ b/samples/advanced/fileread/amg_cf_sample.f90
@@ -659,7 +659,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_cf_sample ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       !
       ! input files
diff --git a/samples/advanced/fileread/amg_df_sample.f90 b/samples/advanced/fileread/amg_df_sample.f90
index ad3b72ba..2f8495d2 100644
--- a/samples/advanced/fileread/amg_df_sample.f90
+++ b/samples/advanced/fileread/amg_df_sample.f90
@@ -659,7 +659,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_df_sample ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       !
       ! input files
diff --git a/samples/advanced/fileread/amg_sf_sample.f90 b/samples/advanced/fileread/amg_sf_sample.f90
index d9a6378c..3b4c2d1a 100644
--- a/samples/advanced/fileread/amg_sf_sample.f90
+++ b/samples/advanced/fileread/amg_sf_sample.f90
@@ -659,7 +659,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_sf_sample ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       !
       ! input files
diff --git a/samples/advanced/fileread/amg_zf_sample.f90 b/samples/advanced/fileread/amg_zf_sample.f90
index 7575cb39..acabe1ba 100644
--- a/samples/advanced/fileread/amg_zf_sample.f90
+++ b/samples/advanced/fileread/amg_zf_sample.f90
@@ -659,7 +659,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_zf_sample ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       !
       ! input files
diff --git a/samples/advanced/pdegen/amg_d_genpde_mod.F90 b/samples/advanced/pdegen/amg_d_genpde_mod.F90
index abed2bc6..1a529c22 100644
--- a/samples/advanced/pdegen/amg_d_genpde_mod.F90
+++ b/samples/advanced/pdegen/amg_d_genpde_mod.F90
@@ -736,7 +736,7 @@ contains
       npdims = 1
 #else 
       npp = np
-      call mpi_dims_create(npp,3,npdims,minfo)
+      call mpi_dims_create(npp,2,npdims,minfo)
 #endif
       npx = npdims(1)
       npy = npdims(2)
diff --git a/samples/advanced/pdegen/amg_d_pde2d.F90 b/samples/advanced/pdegen/amg_d_pde2d.F90
index 23f9f117..6e86d4d9 100644
--- a/samples/advanced/pdegen/amg_d_pde2d.F90
+++ b/samples/advanced/pdegen/amg_d_pde2d.F90
@@ -634,7 +634,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_d_pde2d ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input data
       !
diff --git a/samples/advanced/pdegen/amg_d_pde3d.F90 b/samples/advanced/pdegen/amg_d_pde3d.F90
index fe51c67e..35fe4e47 100644
--- a/samples/advanced/pdegen/amg_d_pde3d.F90
+++ b/samples/advanced/pdegen/amg_d_pde3d.F90
@@ -638,7 +638,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_d_pde3d ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input data
       !
diff --git a/samples/advanced/pdegen/amg_s_genpde_mod.F90 b/samples/advanced/pdegen/amg_s_genpde_mod.F90
index 44832bc4..f7360127 100644
--- a/samples/advanced/pdegen/amg_s_genpde_mod.F90
+++ b/samples/advanced/pdegen/amg_s_genpde_mod.F90
@@ -736,7 +736,7 @@ contains
       npdims = 1
 #else 
       npp = np
-      call mpi_dims_create(npp,3,npdims,minfo)
+      call mpi_dims_create(npp,2,npdims,minfo)
 #endif
       npx = npdims(1)
       npy = npdims(2)
diff --git a/samples/advanced/pdegen/amg_s_pde2d.F90 b/samples/advanced/pdegen/amg_s_pde2d.F90
index 9b325d79..a99c19ed 100644
--- a/samples/advanced/pdegen/amg_s_pde2d.F90
+++ b/samples/advanced/pdegen/amg_s_pde2d.F90
@@ -634,7 +634,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_s_pde2d ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input data
       !
diff --git a/samples/advanced/pdegen/amg_s_pde3d.F90 b/samples/advanced/pdegen/amg_s_pde3d.F90
index d7621d1e..8adbdf14 100644
--- a/samples/advanced/pdegen/amg_s_pde3d.F90
+++ b/samples/advanced/pdegen/amg_s_pde3d.F90
@@ -638,7 +638,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_s_pde3d ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input data
       !
diff --git a/samples/simple/fileread/amg_cexample_1lev.f90 b/samples/simple/fileread/amg_cexample_1lev.f90
index aa55ba7a..341e94c0 100644
--- a/samples/simple/fileread/amg_cexample_1lev.f90
+++ b/samples/simple/fileread/amg_cexample_1lev.f90
@@ -328,7 +328,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_cexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_cexample_ml.f90 b/samples/simple/fileread/amg_cexample_ml.f90
index b5c6ec80..d606c9a3 100644
--- a/samples/simple/fileread/amg_cexample_ml.f90
+++ b/samples/simple/fileread/amg_cexample_ml.f90
@@ -378,7 +378,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_cexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_dexample_1lev.f90 b/samples/simple/fileread/amg_dexample_1lev.f90
index a9584959..7f6bebc3 100644
--- a/samples/simple/fileread/amg_dexample_1lev.f90
+++ b/samples/simple/fileread/amg_dexample_1lev.f90
@@ -328,7 +328,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_dexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_dexample_ml.f90 b/samples/simple/fileread/amg_dexample_ml.f90
index b84fd400..9822aec0 100644
--- a/samples/simple/fileread/amg_dexample_ml.f90
+++ b/samples/simple/fileread/amg_dexample_ml.f90
@@ -378,7 +378,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_dexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_sexample_1lev.f90 b/samples/simple/fileread/amg_sexample_1lev.f90
index f7ad7582..6f0114c6 100644
--- a/samples/simple/fileread/amg_sexample_1lev.f90
+++ b/samples/simple/fileread/amg_sexample_1lev.f90
@@ -328,7 +328,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_sexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_sexample_ml.f90 b/samples/simple/fileread/amg_sexample_ml.f90
index 46b4816e..f532b8cf 100644
--- a/samples/simple/fileread/amg_sexample_ml.f90
+++ b/samples/simple/fileread/amg_sexample_ml.f90
@@ -378,7 +378,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_sexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_zexample_1lev.f90 b/samples/simple/fileread/amg_zexample_1lev.f90
index 273fefe7..76b5f4eb 100644
--- a/samples/simple/fileread/amg_zexample_1lev.f90
+++ b/samples/simple/fileread/amg_zexample_1lev.f90
@@ -328,7 +328,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_zexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/fileread/amg_zexample_ml.f90 b/samples/simple/fileread/amg_zexample_ml.f90
index d0ce4e66..a6de8ea0 100644
--- a/samples/simple/fileread/amg_zexample_ml.f90
+++ b/samples/simple/fileread/amg_zexample_ml.f90
@@ -378,7 +378,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_zexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(mtrx,inp_unit)
diff --git a/samples/simple/pdegen/amg_dexample_1lev.f90 b/samples/simple/pdegen/amg_dexample_1lev.f90
index 5667f0ab..e20bfefa 100644
--- a/samples/simple/pdegen/amg_dexample_1lev.f90
+++ b/samples/simple/pdegen/amg_dexample_1lev.f90
@@ -257,7 +257,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_dexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       
       ! read input parameters
diff --git a/samples/simple/pdegen/amg_dexample_ml.f90 b/samples/simple/pdegen/amg_dexample_ml.f90
index 1ed41f4d..9574a5c4 100644
--- a/samples/simple/pdegen/amg_dexample_ml.f90
+++ b/samples/simple/pdegen/amg_dexample_ml.f90
@@ -320,7 +320,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_dexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(choice,inp_unit)
diff --git a/samples/simple/pdegen/amg_sexample_1lev.f90 b/samples/simple/pdegen/amg_sexample_1lev.f90
index 4e023221..bc542412 100644
--- a/samples/simple/pdegen/amg_sexample_1lev.f90
+++ b/samples/simple/pdegen/amg_sexample_1lev.f90
@@ -257,7 +257,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_sexample_1lev ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       
       ! read input parameters
diff --git a/samples/simple/pdegen/amg_sexample_ml.f90 b/samples/simple/pdegen/amg_sexample_ml.f90
index 03d59633..61f6b86e 100644
--- a/samples/simple/pdegen/amg_sexample_ml.f90
+++ b/samples/simple/pdegen/amg_sexample_ml.f90
@@ -320,7 +320,9 @@ contains
           write(psb_err_unit,*) 'Opened file ',trim(filename),' for input'
         end if
       else
-        inp_unit=psb_inp_unit
+        write(psb_err_unit,*) 'Usage: amg_sexample_ml ctrl-file '
+        call psb_abort(ctxt)
+        stop        
       end if
       ! read input parameters
       call read_data(choice,inp_unit)