diff --git a/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java b/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
index c49ea058..daeaa1dc 100644
--- a/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
+++ b/app/src/androidTest/java/org/solovyev/android/calculator/plot/PlotEditFunctionFragmentTest.java
@@ -1,15 +1,21 @@
 package org.solovyev.android.calculator.plot;
 
+import org.hamcrest.Matchers;
 import org.junit.Test;
 import org.solovyev.android.calculator.R;
 import org.solovyev.android.calculator.functions.CppFunction;
+import org.solovyev.android.calculator.functions.FunctionParamsView;
 
 import static android.support.test.espresso.Espresso.onView;
 import static android.support.test.espresso.action.ViewActions.click;
+import static android.support.test.espresso.action.ViewActions.typeTextIntoFocusedView;
 import static android.support.test.espresso.assertion.ViewAssertions.matches;
+import static android.support.test.espresso.matcher.ViewMatchers.hasFocus;
 import static android.support.test.espresso.matcher.ViewMatchers.isDisplayed;
 import static android.support.test.espresso.matcher.ViewMatchers.withId;
+import static android.support.test.espresso.matcher.ViewMatchers.withTagValue;
 import static android.support.test.espresso.matcher.ViewMatchers.withText;
+import static org.hamcrest.Matchers.allOf;
 import static org.hamcrest.Matchers.not;
 
 public class PlotEditFunctionFragmentTest extends BasePlotTest {
@@ -35,4 +41,22 @@ public class PlotEditFunctionFragmentTest extends BasePlotTest {
 
         onView(withId(R.id.function_params_add)).check(matches(not(isDisplayed())));
     }
+
+    @Test
+    public void testShouldProvideDefaultParamNames() throws Exception {
+        openFunctionEditor();
+
+        onView(withId(R.id.function_params_add)).perform(click());
+        onView(allOf(hasFocus(), withTagValue(Matchers.<Object>equalTo(FunctionParamsView.PARAM_VIEW_TAG)))).check(matches(withText("x")));
+    }
+
+    @Test
+    public void testShouldSelectParamOnFocus() throws Exception {
+        openFunctionEditor();
+
+        onView(withId(R.id.function_params_add)).perform(click());
+        // check "select-on-focus" attribute
+        onView(allOf(hasFocus(), withTagValue(Matchers.<Object>equalTo(FunctionParamsView.PARAM_VIEW_TAG)))).perform(typeTextIntoFocusedView("y"));
+        onView(allOf(hasFocus(), withTagValue(Matchers.<Object>equalTo(FunctionParamsView.PARAM_VIEW_TAG)))).check(matches(withText("y")));
+    }
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/solovyev/android/calculator/functions/FunctionParamsView.java b/app/src/main/java/org/solovyev/android/calculator/functions/FunctionParamsView.java
index 7177b416..0f58905f 100644
--- a/app/src/main/java/org/solovyev/android/calculator/functions/FunctionParamsView.java
+++ b/app/src/main/java/org/solovyev/android/calculator/functions/FunctionParamsView.java
@@ -48,6 +48,7 @@ import org.solovyev.android.calculator.Preferences;
 import org.solovyev.android.calculator.R;
 
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 import javax.annotation.Nonnull;
@@ -60,6 +61,7 @@ public class FunctionParamsView extends LinearLayout {
 
     @Nonnull
     public static final String PARAM_VIEW_TAG = "param-view";
+    private static final List<String> PARAM_NAMES = Arrays.asList("x", "y", "z", "t", "a", "b", "c");
     private static final int FOOTERS = 1;
     private static final int PARAM_VIEW_INDEX = 3;
     private static final int START_ROW_ID = App.generateViewId();
@@ -106,7 +108,7 @@ public class FunctionParamsView extends LinearLayout {
         addButton.setOnClickListener(new View.OnClickListener() {
             @Override
             public void onClick(View v) {
-                final LinearLayout rowView = addParam(null);
+                final LinearLayout rowView = addParam(generateParamName());
                 final EditText paramView = getParamView(rowView);
                 paramView.requestFocus();
             }
@@ -116,6 +118,13 @@ public class FunctionParamsView extends LinearLayout {
         addView(headerView, new ViewGroup.LayoutParams(MATCH_PARENT, WRAP_CONTENT));
     }
 
+    @Nullable
+    private String generateParamName() {
+        final List<String> available = new ArrayList<>(PARAM_NAMES);
+        available.removeAll(getParams());
+        return available.size() > 0 ? available.get(0) : null;
+    }
+
     @NonNull
     private ImageButton makeButton(int icon) {
         final ImageButton addButton = new ImageButton(getContext());
@@ -187,6 +196,7 @@ public class FunctionParamsView extends LinearLayout {
             paramView.setText(param);
         }
         paramView.setOnFocusChangeListener(getOnFocusChangeListener());
+        paramView.setSelectAllOnFocus(true);
         paramView.setInputType(EditorInfo.TYPE_CLASS_TEXT);
         paramView.setId(id);
         paramView.setTag(PARAM_VIEW_TAG);