--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants.java	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants.java	Mon Jan 20 12:44:16 2014 +0100
@@ -1367,5 +1367,7 @@
     String current_gauge();
 
     String suggested_label();
+
+    String negative_values_not_allowed_for_to();
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants.properties	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants.properties	Mon Jan 20 12:44:16 2014 +0100
@@ -715,3 +715,4 @@
 FEDSTATE_KM = Station (Federal State)
 
 official_regulation = official Regulation
+negative_values_not_allowed_for_to=Keine negativen Werte bei 'bis' erlaubt.

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants_de.properties	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants_de.properties	Mon Jan 20 12:44:16 2014 +0100
@@ -713,3 +713,4 @@
 WATERBODY = Gewässer
 FEDSTATE_KM = Landes-Stationierung
 official_regulation = amtl. Festlegung
+negative_values_not_allowed_for_to=Keine negativen Werte bei 'bis' erlaubt.

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants_en.properties	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/FLYSConstants_en.properties	Mon Jan 20 12:44:16 2014 +0100
@@ -654,3 +654,4 @@
 # Get Feature Info Window
 PATH = Path
 official_regulation = Official Regulation
+negative_values_not_allowed_for_to=Negative are not allowed for 'to'.

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/event/RangeFilterEvent.java	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/event/RangeFilterEvent.java	Mon Jan 20 12:44:16 2014 +0100
@@ -18,25 +18,21 @@
     protected Float from;
     protected Float to;
 
+    private static Float asFloat(NumberFormat nf, String x) {
+        try {
+            return Float.valueOf((float)nf.parse(x));
+        }
+        catch (NumberFormatException nfe) {
+            return Float.NaN;
+        }
+    }
+
 
     public RangeFilterEvent(String from, String to) {
         NumberFormat nf = NumberFormat.getDecimalFormat();
-        double d;
 
-        try {
-            d = nf.parse(from);
-            this.from = Float.valueOf(String.valueOf(d));
-        }
-        catch(NumberFormatException nfe) {
-            this.from = Float.NaN;
-        }
-        try {
-            d = nf.parse(to);
-            this.to = Float.valueOf(String.valueOf(d));
-        }
-        catch(NumberFormatException nfe) {
-            this.to = Float.NaN;
-        }
+        this.from = asFloat(nf, from);
+        this.to = asFloat(nf, to);
     }
 
 

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/DistancePanel.java	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/DistancePanel.java	Mon Jan 20 12:44:16 2014 +0100
@@ -598,22 +598,28 @@
 
         Criterion combinedFilter = null;
         Criterion locationFilter = null;
+
         if (from.equals(Float.NaN) && to.equals(Float.NaN)) {
             locationsTable.clearCriteria();
             distancesTable.clearCriteria();
             filterResultCount.setValue("");
             return;
         }
-        else if (from.equals(Float.NaN)) {
-            combinedFilter = new Criterion("to", OperatorId.LESS_OR_EQUAL, to);
+
+        if (from.equals(Float.NaN)) {
+            combinedFilter =
+                new Criterion("to", OperatorId.LESS_OR_EQUAL, to);
+
             locationFilter =
                 new Criterion("from", OperatorId.LESS_OR_EQUAL, to);
+
             locationsTable.filterData(locationFilter);
             distancesTable.filterData(combinedFilter);
             filterResultCount.setValue(currentFiltered.getRecords().length);
             return;
         }
-        else if (to.equals(Float.NaN)) {
+
+        if (to.equals(Float.NaN)) {
             combinedFilter =
                 new Criterion("from", OperatorId.GREATER_OR_EQUAL, from);
         }

--- a/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/WaterlevelGroundPanel.java	Mon Jan 13 11:52:22 2014 +0100
+++ b/gwt-client/src/main/java/org/dive4elements/river/client/client/ui/WaterlevelGroundPanel.java	Mon Jan 20 12:44:16 2014 +0100
@@ -8,6 +8,8 @@
 
 package org.dive4elements.river.client.client.ui;
 
+import java.util.List;
+
 public class WaterlevelGroundPanel extends DistancePanel {
 
     private static final long serialVersionUID = 6598703468619862469L;
@@ -123,5 +125,16 @@
         // We don't need a helper panel here. But we have to override this
         // method to avoid the table creation in the parent class.
     }
+
+    @Override
+    protected void validateTo(List<String> errors) {
+        double to = distancePanel.getTo();
+
+        if (to < 0d) {
+            distancePanel.setTo(max);
+            errors.add(MSG.negative_values_not_allowed_for_to());
+        }
+        super.validateTo(errors);
+    }
 }
 // vim:set ts=4 sw=4 si et sta sts=4 fenc=utf8 :