diff --git a/src/main/java/eu/omp/irap/vespa/epntapclient/view/ParamField.java b/src/main/java/eu/omp/irap/vespa/epntapclient/view/ParamField.java
index 1917476..1ed8098 100644
--- a/src/main/java/eu/omp/irap/vespa/epntapclient/view/ParamField.java
+++ b/src/main/java/eu/omp/irap/vespa/epntapclient/view/ParamField.java
@@ -51,14 +51,16 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class StringField extends ParamField {
+		JTextField field;
+
 		StringField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
-			JTextField field = new JTextField();
-			addChangeListener(field, e -> onUpdate(field));
+			field = new JTextField();
+			addChangeListener(field, e -> onUpdate());
 			this.add(field);
 		}
 
-		private void onUpdate(JTextField field) {
+		private void onUpdate() {
 			if ("".equals(field.getText())) {
 				requestView.updateParam(paramName, null);
 			} else {
@@ -68,14 +70,16 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class FloatField extends ParamField {
+		JTextField field;
+
 		FloatField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
-			JTextField field = new JTextField();
-			addChangeListener(field, e -> onUpdate(field));
+			field = new JTextField();
+			addChangeListener(field, e -> onUpdate());
 			this.add(field);
 		}
 
-		private void onUpdate(JTextField field) {
+		private void onUpdate() {
 			if ("".equals(field.getText())) {
 				field.setBackground(Color.WHITE);
 				requestView.updateParam(paramName, null);
@@ -91,13 +95,16 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class DateRangeField extends ParamField {
+		JTextField fieldMin;
+		JTextField fieldMax;
+
 		DateRangeField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
-			JTextField fieldMin = new JTextField();
+			fieldMin = new JTextField();
 			addChangeListener(fieldMin, e -> onUpdate(fieldMin, MIN_SUFFIX));
 			this.add(fieldMin);
 
-			JTextField fieldMax = new JTextField();
+			fieldMax = new JTextField();
 			addChangeListener(fieldMax, e -> onUpdate(fieldMax, MAX_SUFFIX));
 			this.add(fieldMax);
 		}
@@ -154,14 +161,17 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class TargetNameField extends ParamField {
+		JTextField field;
+
 		TargetNameField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
-			JTextField field = new JTextField();
-			addChangeListener(field, e -> onUpdate(field));
+			field = new JTextField();
+			addChangeListener(field, e -> onUpdate());
+			field.setEditable(true);
 			this.add(field);
 		}
 
-		private void onUpdate(JTextField field) {
+		private void onUpdate() {
 			// TODO: add resolver
 			if ("".equals(field.getText())) {
 				requestView.updateParam(paramName, null);
@@ -172,15 +182,17 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class DataProductTypeField extends ParamField {
+		JTextField field;
+
 		DataProductTypeField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
-			JTextField field = new JTextField();
+			field = new JTextField();
 			// TODO: listbox with enumerated values instead of JTextField
-			addChangeListener(field, e -> onUpdate(field));
+			addChangeListener(field, e -> onUpdate());
 			this.add(field);
 		}
 
-		private void onUpdate(JTextField field) {
+		private void onUpdate() {
 			if ("".equals(field.getText())) {
 				requestView.updateParam(paramName, null);
 			} else {
@@ -190,15 +202,17 @@ public abstract class ParamField extends JPanel {
 	}
 
 	public static class TargetClassField extends ParamField {
+		JTextField field;
+
 		TargetClassField(RequestView requestView, String paramName) {
 			super(requestView, paramName);
 			JTextField field = new JTextField();
 			// TODO: listbox with enumerated values instead of JTextField
-			addChangeListener(field, e -> onUpdate(field));
+			addChangeListener(field, e -> onUpdate());
 			this.add(field);
 		}
 
-		private void onUpdate(JTextField field) {
+		private void onUpdate() {
 			if ("".equals(field.getText())) {
 				requestView.updateParam(paramName, null);
 			} else {
--
libgit2 0.21.2