diff --git a/src/main/java/org/gcube/nlphub/NLPUploader.java b/src/main/java/org/gcube/nlphub/NLPUploader.java
index 4671a04..24091c6 100644
--- a/src/main/java/org/gcube/nlphub/NLPUploader.java
+++ b/src/main/java/org/gcube/nlphub/NLPUploader.java
@@ -79,6 +79,7 @@ public class NLPUploader extends HttpServlet {
 	private void handleFreeText(HttpServletRequest request, HttpServletResponse response)
 			throws ServletException, IOException {
 		String freeText = request.getParameter("freetext");
+		System.out.println("freeText: " + freeText);
 		byte[] content = freeText.getBytes("UTF-8");
 		String fileName = generateFileName();
 		PrintWriter writer = response.getWriter();
diff --git a/src/main/webapp/index.jsp b/src/main/webapp/index.jsp
index 2e3eda4..4cea94a 100644
--- a/src/main/webapp/index.jsp
+++ b/src/main/webapp/index.jsp
@@ -533,7 +533,13 @@
 			}
 		}
 
-		return mergeIndices(indices);
+		var indices2 = [];
+		for(var i=0; i<indices.length; i++) {
+			if(typeof (indices[i]) != 'undefined')
+				indices2[indices2.length] = indices[i];
+		}
+		
+		return mergeIndices(indices2);
 	}
 
 	mergeIndices = function(indices) {
diff --git a/src/main/webapp/js/merge.js b/src/main/webapp/js/merge.js
index 5fe08f7..5df986a 100644
--- a/src/main/webapp/js/merge.js
+++ b/src/main/webapp/js/merge.js
@@ -80,7 +80,11 @@ compareSegmentList = function(list1, list2) {
 	return true;
 }
 
-
+/**
+ * mergeAll: merge indices
+ * parameters: indices = Array of Array of indices (index = [start, end])
+ * Example: indices = [[[1,2], [4,5]], [[0,5], [7,11]]];
+ */
 
 mergeAll = function(indices) {
 	var m = [];