diff --git a/src/_data/translate.yml b/src/_data/translate.yml
index 51a8fe7..ab28b2e 100644
--- a/src/_data/translate.yml
+++ b/src/_data/translate.yml
@@ -94,6 +94,7 @@ en:
     twoTail: Two Tails
   twoMean:
     Samples: Samples
+    alertAtLeastOne: Group 1 and Group 2 must both have at least one element.
     diffOfMean: 'Difference of Means (Mean 1 - Mean 2):'
     diffOfSampleMean: 'Difference of Means (Randomized Samples):'
     differences: Differences
@@ -249,6 +250,7 @@ es:
     twoTail: Dos colas
   twoMean:
     Samples: Muestras
+    alertAtLeastOne: Grupo 1 y Grupo 2 tienen que tener ambos al menos un elemento.
     diffOfMean: 'Diferencia entre Medias (Media 1 - Media 2):'
     diffOfSampleMean: 'Differencia entre medias (de muestras aleatorizadas):'
     differences: Diferencias
diff --git a/src/translationSource/translationData.csv b/src/translationSource/translationData.csv
index 46ac9e9..65a76ad 100644
--- a/src/translationSource/translationData.csv
+++ b/src/translationSource/translationData.csv
@@ -105,6 +105,7 @@ Original Dataset Difference of Means:	Diferencia de Medias en Datos Originales:
 Mean of Sample Differences:	Media de las Diferencias:	twoMean.meanSampleDiff
 Standard Deviation:	Desviación Estándar:	twoMean.stdSampleDiff
 Proportion of Extreme Differences	Proporción de Diferencias Extremas:	twoMean.proportionSelcted
+Group 1 and Group 2 must both have at least one element.	Grupo 1 y Grupo 2 tienen que tener ambos al menos un elemento.	twoMean.alertAtLeastOne
 Two Proportions	Dos Proporciones	twoProportions.title
 Enter Data:	Teclee los Datos	twoProportions.enterData
 Group A	Grupo A	twoProportions.groupA
diff --git a/src/twoMean/twoMean.js b/src/twoMean/twoMean.js
index 893a167..44181ea 100644
--- a/src/twoMean/twoMean.js
+++ b/src/twoMean/twoMean.js
@@ -102,7 +102,12 @@ export class TwoMean {
 
   loadData() {
     let rawData = this.parseData(this.csvInput.value.trim());
-    this.updateData(rawData);
+    if (!rawData[0] || !rawData[0].length || !rawData[1] || !rawData[1].length) {
+      alert(translation.twoMean.alertAtLeastOne);
+    }
+    else {
+      this.updateData(rawData);
+    }
   }
 
   parseData(dataText) {
@@ -130,7 +135,6 @@ export class TwoMean {
     this.sampleDiffs = [];
 
     let dataValues = data[0].concat(data[1]);
-    console.log(dataValues);
     if (dataValues.length) {
       let min = Math.min.apply(undefined, dataValues);
       let max = Math.max.apply(undefined, dataValues);