diff --git a/src/main/resources/log4j.properties b/src/main/resources/log4j.properties
new file mode 100644
index 0000000..0641702
--- /dev/null
+++ b/src/main/resources/log4j.properties
@@ -0,0 +1,8 @@
+log4j.rootLogger=INFO,stdout
+log4j.logger.com.endeca=INFO
+# Logger for crawl metrics
+log4j.logger.com.endeca.itl.web.metrics=INFO
+
+log4j.appender.stdout=org.apache.log4j.ConsoleAppender
+log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
+log4j.appender.stdout.layout.ConversionPattern=%p\t%d{ISO8601}\t%r\t%c\t[%t]\t%m%n
diff --git a/src/main/webapp/js/main.js b/src/main/webapp/js/main.js
index d3a4079..f4054f4 100644
--- a/src/main/webapp/js/main.js
+++ b/src/main/webapp/js/main.js
@@ -102,12 +102,12 @@ $(document).ready(function() {
 								},
 								onSuccess : function(files, data, xhr) {
 									hideProgress();
-									console.log('' + data.language);
+									//console.log('' + data.language);
 									checkLanguage(data.language);
 									selectAnnotationsByLanguage();
 									$("#reset-upload").css("display",
 											"inline");
-									console.log("files: " + files);
+									//console.log("files: " + files);
 									$("#file-info").empty();
 									$("#file-info")
 											.append(
@@ -373,6 +373,7 @@ showProgress = function() {
 	$(".progress-circular-div").css("left", left);
 	$(".progress-circular-div").css("top", top);
 	$(".hidden-div").css("display", "block");
+	$(".hidden-div").show();
 }
 
 /*
@@ -380,6 +381,7 @@ showProgress = function() {
  */
 hideProgress = function() {
 	$(".hidden-div").css("display", "none");
+	$(".hidden-div").hide();
 }
 
 /*
@@ -471,7 +473,7 @@ getOutputJson = function(message) {
 	parameters += "&plink=" + encodeURI(publicLink);
 	parameters += "&lang=" + $("#language-select").val();
 	parameters += "&tobemap=" + encodeURI(tobemap);
-	console.log(parameters);
+	//console.log(parameters);
 
 	$.ajax({
 		url : "/nlphub/nlphub-mapper-servlet?" + parameters,
@@ -479,7 +481,7 @@ getOutputJson = function(message) {
 		async : true,
 		success : function(data, stato) {
 			hideProgress();
-			console.log(data);
+			//console.log(data);
 			if ((typeof (data.response) != "undefined")
 					&& (data.response.trim().toUpperCase() == "ERROR")) {
 				alert("ERROR\n" + data.message);
@@ -604,49 +606,46 @@ rewriteText = function(annotation, color) {
 	var G = enhanceColor(complement.substring(2,4));
 	var B = enhanceColor(complement.substring(4));
 	complement = "#" + R + G + B;
-	console.log("-getIndices: start");
-	var indices = getIndices(annotation);
-	console.log("-getIndices: end");
-	$("#result-header-right").empty();
-	$("#result-header-right").append("<span style='color:" + color + ";'>" + annotation + "</span> occurs " + indices.length + " times.");
-	var indexedText = "";
+	showProgress();
+	$(".hidden-div").show();
+	window.setTimeout(function() {
+		var indices = getIndices(annotation);
+		$(".hidden-div").hide();	
+
+		$("#result-header-right").empty();
+		$("#result-header-right").append("<span style='color:" + color + ";'>" + annotation + "</span> occurs " + indices.length + " times.");
+		var indexedText = "";
+
+		if ((typeof (indices) == 'undefined') || (indices.length == 0)) {
+			indexedText = resultText;
+			indexedText = indexedText.replace(/\n/g, "<br>");
+			indexedText = indexedText.replace(/</g, "&lt;");
+			indexedText = indexedText.replace(/>/g, "&gt;");
+			$("#result-text-div").append("<p>" + indexedText + "</p>");
+			return;
+		}
+
+		var t = 0;
+		var offset = 0;
+		for (var i = 0; i < indices.length; i++) {
+			var index = indices[i];
+			var start = index[0];
+			var end = index[1];
+			indexedText += resultText.substring(t, start);
+
+			var colored = "<span style='color:" + color + "; background:"
+					+ complement + "; font-weight:bold;'>"
+					+ resultText.substring(start, end) + "</span>";
+			indexedText += colored;
+			t = end;
+		}
+		if (t < resultText.length)
+			indexedText += resultText.substring(t);
 
-	if ((typeof (indices) == 'undefined') || (indices.length == 0)) {
-		indexedText = resultText;
 		indexedText = indexedText.replace(/\n/g, "<br>");
-		indexedText = indexedText.replace(/</g, "&lt;");
-		indexedText = indexedText.replace(/>/g, "&gt;");
 		$("#result-text-div").append("<p>" + indexedText + "</p>");
-		return;
-	}
-
-	var t = 0;
-	var offset = 0;
-	for (var i = 0; i < indices.length; i++) {
-		var index = indices[i];
-		var start = index[0];
-		var end = index[1];
-		indexedText += resultText.substring(t, start);
-		/*
-		offset += countSubstringOccurrencies(resultText.substring(t, start),
-				"\n");
-		offset += countSubstringOccurrencies(resultText.substring(t, start),
-				"\r");
-		offset += countSubstringOccurrencies(resultText.substring(t, start),
-				"\t");
-		start += offset;
-		end += offset;*/
-		var colored = "<span style='color:" + color + "; background:"
-				+ complement + "; font-weight:bold;'>"
-				+ resultText.substring(start, end) + "</span>";
-		indexedText += colored;
-		t = end;
-	}
-	if (t < resultText.length)
-		indexedText += resultText.substring(t);
-
-	indexedText = indexedText.replace(/\n/g, "<br>");
-	$("#result-text-div").append("<p>" + indexedText + "</p>");
+			
+	}, 50);
 }
 
 /*
@@ -699,14 +698,12 @@ getIndices = function(annotation) {
  * Merge the indices
  */
 mergeIndices = function(indices) {
-	console.log("--mergeIndices start");
 	var newIndices = [];
 	//console.log("--mergeIndices: indices.length=" + indices.length);
 	if (indices.length == 1)
 		newIndices = indices[0];
 	else
 		newIndices = mergeAll(indices);
-	console.log("--mergeIndices end");
 	return newIndices;
 }
 
diff --git a/src/main/webapp/js/merge.js b/src/main/webapp/js/merge.js
index 67576db..cf52ceb 100644
--- a/src/main/webapp/js/merge.js
+++ b/src/main/webapp/js/merge.js
@@ -43,43 +43,6 @@ compareSegments = function(s1, s2) {
 	return (s1[0] - s2[0]);
 }
 
-cleanSegmentList = function(list) {
-	var cleaned = [];
-	for(var i=0; i<list.length; i++) {
-		if(cleaned.length == 0)
-			cleaned[cleaned.length] = list[i];
-		else {
-			var found = false;			
-			for(var j=0; j<cleaned.length; j++) {
-				if(compareSegment(cleaned[j], list[i]) == 0) {
-					if(cleaned[j][0] > list[i][0])	
-						cleaned[j] = list[i];
-					found = true;
-					break;
-				}
-				if(compareSegment(cleaned[j], list[i]) < 0) {
-					if(cleaned[j][0] <= list[i][0]) 
-						cleaned[j] = [cleaned[j][0], list[i][1]];
-					else
-						cleaned[j] = [list[i][0], cleaned[j][1]];
-					found = true;
-				}
-			}
-			if(!found) cleaned[cleaned.length] = list[i];
-		}
-	 }
-	return cleaned;
-}
-
-compareSegmentList = function(list1, list2) {
-	if(list1.length != list2.length)
-		return false;
-	for(var i=0; i<list1.length; i++)
-		if((list1[i][0] != list2[i][0]) || (list1[i][1] != list2[i][1]))
-			return false;
-	return true;
-}
-
 /**
  * mergeAll: merge indices
  * parameters: indices = Array of Array of indices (index = [start, end])
@@ -87,42 +50,46 @@ compareSegmentList = function(list1, list2) {
  */
 
 mergeAll = function(indices) {
-	console.log("---mergeAll indices.length=" + indices.length);
 	var m = [];
-	for(var i=0; i<indices[0].length; i++) {
-	 	for(var j=1; j<indices.length; j++) {
-	 		for(var k=0; k<indices[j].length; k++) {
-	 			var res = mergeSegment(indices[0][i], indices[j][k]);
-	 			for(var u=0; u<res.length; u++) 
-	 				m[m.length] = res[u];
-	 		}
-	 	}
-	}
-/*	
-	var end = false;
-	var counter = 1;
-	while(!end) {
-		var old = m.slice();
-		m = cleanSegmentList(m);
-		//console.log(m);
-		end = compareSegmentList(old, m);
-		counter++;
-		if(counter == 100)
-			end = true;
-	}
-	return m.sort(compareSegments);*/
 	
+	// first of all: creates a 1-dimension array with all data
+	for(var i=0; i<indices.length; i++) {
+		m = m.concat(indices[i]);
+	}
+	
+	//
+	// second step: sort the array
+	// for our purposes a segment is 'lower than' another segment if the left value of the segment 
+	// is lower than the left value of the other segment. In other words:
+	// [a, b] < [c, d] if a < c
+	//
 	m = m.sort(compareSegments);
+	
 	var m2 = [];
+	
+	//
+	// merging procedure:
+	// the procedure uses the functions: 
+	// [1] 'compareSegment'.
+	// when two segment are equals or included compareSegment returns 0
+	// when two segment are intersecting compareSegment returns -1
+	// when two segment have are external (no intersection) compareSegment returns 1
+	//
+	// [2] 'mergeSegment'
+	// returns the "union" of two segments
+	//
 	var current = m[0];
 	for(var i=0; i<m.length; i++) {
 		var cfr = compareSegment(current, m[i]);
 		switch(cfr) {
 		case 0:
 		case -1:
+			// if segments are the same or intersected the result is the merged segment
 			current = mergeSegment(current, m[i])[0];
 			break;
 		default:
+			// if segments are external mergeSegment produce two segments: the first is ready to be stored in the output vector
+			// the second is to be compared with others
 			var s = mergeSegment(current, m[i]);
 			m2[m2.length] = s[0];
 			current = s[1];
@@ -130,7 +97,10 @@ mergeAll = function(indices) {
 		}
 	}
 	
-	if((current[0] != m2[m2.length-1][0]) || (current[1] != m2[m2.length-1][1]))
+	if(m2.length == 0) {
+		m2[0] = current;
+	}
+	else if((current[0] != m2[m2.length-1][0]) || (current[1] != m2[m2.length-1][1]))
 		m2[m2.length] = current;	
 	return m2;
 }
diff --git a/src/main/webapp/merge.html b/src/main/webapp/merge.html
index ec29516..6eaabc7 100644
--- a/src/main/webapp/merge.html
+++ b/src/main/webapp/merge.html
@@ -18,33 +18,33 @@ var indices = [
 //console.log(newIndices);
 // answer is: [0,19], [21,23]
 
-indices = [
+indices1 = [
 	[[7,19], [21,25]],
 	[[1,5], [18,22]]
 ];
 //answer is: [1,5], [7,25]
 
-indices = [
+indices2 = [
 	[[7,16], [21,25]],
 	[[1,5], [18,22]]
 ];
 //answer is: [1,5], [7,16], [18,25]
 
-indices = [
+indices3 = [
 	[[7,16], [21,25]],
 	[[1,5], [18,22]],
 	[[2,30]]
 ];
 //answer is: [1,30]
 
-indices = [
+indices4 = [
 	[[1,4], [5, 8], [21,25]],
 	[[1,5], [18,22]],
 	[[0,2], [11,15], [27,31]]
 ];
 //answer is: [0,8],[11,15],[18,25],[27,31]
 
-
+var indices = indices4;
 var mm = mergeAll(indices);
 
 console.log(mm);