diff --git a/src/Map.js b/src/Map.js
index e98fc54..3ee26a2 100644
--- a/src/Map.js
+++ b/src/Map.js
@@ -52,20 +52,26 @@ function polygonCenter(polygon)
   let minY = -1;
   let maxX = -1;
   let maxY = -1;
-  polygon.forEach((pt) => {
-    if (minX === -1 || minX > pt[0]) {
+  for (const ind in polygon)
+  {
+    const pt = polygon[ind];
+    if (minX === -1 || minX > pt[0]) 
+    {
       minX = pt[0];
     }
-    if (minY === -1 || minY > pt[1]) {
+    if (minY === -1 || minY > pt[1]) 
+    {
       minY = pt[1];
     }
-    if (maxY === -1 || maxY < pt[1]) {
+    if (maxY === -1 || maxY < pt[1]) 
+    {
       maxY = pt[1];
     }
-    if (maxX === -1 || maxX < pt[0]) {
+    if (maxX === -1 || maxX < pt[0]) 
+    {
       maxX = pt[0];
     }
-  })
+  }
   return [(minX + maxX) / 2, (maxY + minY) / 2];
 }
 
@@ -79,20 +85,26 @@ function logoSize(polygon)
   let maxY = -1;
   // We first calculate the maximal coordinates to then output
   // 75% the size of the room
-  polygon.forEach((pt) => {
-    if (minX === -1 || minX > pt[0]) {
+  for (const ind in polygon)
+  {
+    const pt = polygon[ind];
+    if (minX === -1 || minX > pt[0]) 
+    {
       minX = pt[0];
     }
-    if (minY === -1 || minY > pt[1]) {
+    if (minY === -1 || minY > pt[1]) 
+    {
       minY = pt[1];
     }
-    if (maxY === -1 || maxY < pt[1]) {
+    if (maxY === -1 || maxY < pt[1]) 
+    {
       maxY = pt[1];
     }
-    if (maxX === -1 || maxX < pt[0]) {
+    if (maxX === -1 || maxX < pt[0]) 
+    {
       maxX = pt[0];
     }
-  })
+  }
   // For some unknown reason we have to multiply by 10 otherwise
   // it's almost invisible
   const x = 30*(maxX - minX)/4;
@@ -118,20 +130,26 @@ function min_max(request)
   {
     const element = request[ind];
     // element can be a room, a lift, a staircase or toilets
-    (element["surface"]).forEach((pt) => {
-      if (minX === -1 || minX > pt["x"]) {
+    for (const index in element["surface"])
+    {
+      const pt = element["surface"][index];
+      if (minX === -1 || minX > pt["x"]) 
+      {
         minX = pt["x"];
       }
-      if (minY === -1 || minY > pt["y"]) {
+      if (minY === -1 || minY > pt["y"]) 
+      {
         minY = pt["y"];
       }
-      if (maxY === -1 || maxY < pt["y"]) {
+      if (maxY === -1 || maxY < pt["y"]) 
+      {
         maxY = pt["y"];
       }
-      if (maxX === -1 || maxX < pt["x"]) {
+      if (maxX === -1 || maxX < pt["x"]) 
+      {
         maxX = pt["x"];
       }
-    })
+    }
   }
   return [minX, maxX, minY, maxY];
 }
@@ -213,7 +231,8 @@ function list_polygons(request, center, callbackRoomSelected, selectedRoom, call
   {
     const element = request[ind];
     // element can be a room, a lift, a staircase or toilets
-    const positions = (element["surface"]).map((pt) => {
+    const positions = (element["surface"]).map((pt) => 
+    {
       // This function rotates and recenters de the map (should not be necessary once the real data are gathered and
       // only works for third floor)
       // It also changes the objects into lists of two coordinates to make it accepted by the "positions" attribute of