diff --git a/srcF/sfx_main.f90 b/srcF/sfx_main.f90
index 08e627ff6a1946f649621bcc28bc9ba25a7108ac..4032782bb9256f0609be2b982be4ea06bd0efae2 100644
--- a/srcF/sfx_main.f90
+++ b/srcF/sfx_main.f90
@@ -111,7 +111,7 @@ program sfx_main
             write(*, *) ' --dataset [key]'
             write(*, *) '    key = mosaic (default) || irgason || sheba'
             write(*, *) '        = lake || papa || toga || user [files]'
-            write(*, *) '    files = in-common-file in-file out-file'
+            write(*, *) '    files = in-common-file in-file'
             write(*, *) ' --output [file]'
             write(*, *) '    set output filename '
             write(*, *) ' --nmax [value]'
@@ -123,6 +123,7 @@ program sfx_main
                 write(*, *) ' FAILURE! > missing model [key] argument'
                 stop
             end if
+            
             call get_command_argument(i + 1, arg)
             model_id = get_model_id(arg)
             if (model_id == -1) then
@@ -135,6 +136,7 @@ program sfx_main
                 write(*, *) ' FAILURE! > missing dataset [key] argument'
                 stop
             end if
+            
             call get_command_argument(i + 1, arg)
             dataset_id = get_dataset_id(arg)
             if (dataset_id == -1) then
@@ -143,22 +145,21 @@ program sfx_main
             end if
 
             if (dataset_id == dataset_user) then
-                if (i + 4 > num_args) then
+                if (i + 3 > num_args) then
                     write(*, *) ' FAILURE! > incorrect arguments for [user] dataset'
                     stop
                 end if
                 call get_command_argument(i + 2, filename_in_common)
                 call get_command_argument(i + 3, filename_in)
-                call get_command_argument(i + 4, filename_out)
             end if
         end if
         if (trim(arg) == trim(arg_key_output)) then
             if (i == num_args) then
-                write(*, *) ' FAILURE! > missing dataset [key] argument'
+                write(*, *) ' FAILURE! > missing output [key] argument'
                 stop
             end if
-            is_output_set = 1
             call get_command_argument(i + 1, filename_out)
+            is_output_set = 1
         end if
         if (trim(arg) == trim(arg_key_nmax)) then
             if (i == num_args) then
@@ -251,33 +252,28 @@ program sfx_main
     if (dataset_id == dataset_mosaic) then
         filename_in_common = 'data/MOSAiC_zh.txt'
         filename_in = 'data/MOSAiC.txt'
-        if (is_output_set == 0) filename_out = 'out_MOSAiC.txt'
     else if (dataset_id == dataset_irgason) then
         filename_in_common = 'data/IRGASON_zh.txt'
         filename_in = 'data/Irgason1.txt'
-        if (is_output_set == 0) filename_out = 'out_IRGASON1.txt'
     else if (dataset_id == dataset_sheba) then
         filename_in_common = 'data/Sheba1_zh.txt'
         filename_in = 'data/Sheba1.txt'
-        if (is_output_set == 0) filename_out = 'out_Sheba.txt'
     else if (dataset_id == dataset_lake) then
         filename_in_common = 'data/Kuivajarvi_zh.txt'
         filename_in = 'data/Kuivajarvi.txt'
-        if (is_output_set == 0) filename_out = 'out_Kuivajarvi.txt'
     else if (dataset_id == dataset_papa) then
         filename_in_common = 'data/Papa_zh.txt'
         filename_in = 'data/Papa.txt'
-        if (is_output_set == 0) filename_out = 'out_Papa.txt'
     else if (dataset_id == dataset_toga) then
         filename_in_common = 'data/Toga_zh.txt'
         filename_in = 'data/Toga.txt'
-        if (is_output_set == 0) filename_out = 'out_Toga.txt'
     else if (dataset_id == dataset_user) then
         ! ---> skipping
     else
         write(*, *) ' FAILURE! > unknown dataset id: ', dataset_id
         stop
     end if
+    if (is_output_set == 0) filename_out = 'output-' // trim(dataset_name) // '.txt'
 
     write(*, *) ' Running SFX model'
     write(*, *) '   model = ', trim(model_name)