diff --git a/view/nav.py b/view/nav.py
index 45d3d1d..086f527 100644
--- a/view/nav.py
+++ b/view/nav.py
@@ -17,7 +17,7 @@
     icon=":material/bar_chart:",
 )
 
-pg = st.navigation([domain_page, spectrum_page])
+pg = st.navigation([spectrum_page, domain_page])
 st.set_page_config(
     page_title=app_title,
     page_icon="🦈",
diff --git a/view/simulation_fns.py b/view/simulation_fns.py
index 0be0c48..93f099b 100644
--- a/view/simulation_fns.py
+++ b/view/simulation_fns.py
@@ -8,8 +8,7 @@
 from cmtj import *
 from cmtj.models import LayerSB, Solver
 from cmtj.utils import FieldScan, VectorObj, mu0
-from cmtj.utils.procedures import (PIMM_procedure, ResistanceParameters,
-                                   VSD_procedure)
+from cmtj.utils.procedures import PIMM_procedure, ResistanceParameters, VSD_procedure
 
 
 def create_single_domain(id_: str) -> Layer:
@@ -138,7 +137,10 @@ def get_pimm_data(
     sim_time=16e-9,
 ):
     htheta, hphi = get_axis_angles(H_axis)
-    Hscan, Hvecs = FieldScan.amplitude_scan(Hmin, Hmax, Hsteps, htheta, hphi)
+    hmin, hmax = min([Hmin, Hmax]), max([Hmin, Hmax])  # fix user input
+    Hscan, Hvecs = FieldScan.amplitude_scan(
+        hmin, hmax, Hsteps, htheta, hphi, back=st.session_state["Hreturn"]
+    )
     j, rparams = prepare_simulation()
     spec, freqs, out = PIMM_procedure(
         j,
@@ -170,7 +172,8 @@ def get_vsd_data(
     Hoex_mag=500,
 ):
     htheta, hphi = get_axis_angles(H_axis)
-    Hscan, Hvecs = FieldScan.amplitude_scan(Hmin, Hmax, Hsteps, htheta, hphi)
+    hmin, hmax = min([Hmin, Hmax]), max([Hmin, Hmax])  # fix user input
+    Hscan, Hvecs = FieldScan.amplitude_scan(hmin, hmax, Hsteps, htheta, hphi)
     j, rparams = prepare_simulation()
     frequencies = np.arange(fmin, fmax, step=fstep)
     spec = VSD_procedure(
diff --git a/view/streamlit_app.py b/view/streamlit_app.py
index 08092c4..e22a499 100644
--- a/view/streamlit_app.py
+++ b/view/streamlit_app.py
@@ -113,14 +113,15 @@
             "H axis", options=["x", "y", "z", "xy", "xz", "yz"], key="H_axis", index=0
         )
         st.number_input(
-            "Hmin (kA/m)", min_value=-1000.0, max_value=1000.0, value=-400.0, key="Hmin"
+            "Hmin (kA/m)", min_value=-1e6, max_value=1e6, value=-400.0, key="Hmin"
         )
         st.number_input(
-            "Hmax (kA/m)", min_value=0.0, max_value=1000.0, value=400.0, key="Hmax"
+            "Hmax (kA/m)", min_value=-1e6, max_value=1e6, value=400.0, key="Hmax"
         )
         st.number_input(
             "H steps", min_value=1, max_value=1000, value=50, key="Hsteps", format="%d"
         )
+        st.checkbox("Back-and-forth-field (PIMM only)", value=False, key="Hreturn")
         st.number_input(
             "int_step",
             min_value=1e-14,