diff --git a/demo/www/index.html b/demo/www/index.html
index 9b4a739..bf3a7e2 100644
--- a/demo/www/index.html
+++ b/demo/www/index.html
@@ -28,14 +28,15 @@
         <span class="navbar-toggler-icon"></span>
       </button>
     
-      <div class="collapse navbar-collapse" id="navbarSupportedContent">
-        <ul class="navbar-nav mr-auto">
+      <div class="mx-auto" id="navbarSupportedContent">
+        <ul class="navbar-nav">
+          <span class="navbar-text mr-2">Generator</span>
           <li class="nav-item dropdown">
-            <a class="nav-link dropdown-toggle" href="#" id="navbarDropdown" role="button" data-toggle="dropdown"
-              aria-haspopup="true" aria-expanded="false">
-              Select generator
-            </a>
-            <div class="dropdown-menu" aria-labelledby="navbarDropdown">
+            <button class="btn btn-secondary dropdown-toggle mr-2" type="button" id="generatorDropdown" 
+              data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+              Random
+            </button>
+            <div class="dropdown-menu" aria-labelledby="generatorDropdown">
               <a class="dropdown-item" id="cellular-automata-option">Cellular Automata</a>
               <a class="dropdown-item" id="simple-rooms-option">Simple Rooms</a>
               <a class="dropdown-item" id="bsp-rooms-option">BSP Rooms</a>
@@ -43,10 +44,12 @@
               <a class="dropdown-item" id="drunkard-option">Drunkard Walk</a>
               <a class="dropdown-item" id="maze-option">Maze</a>
               <a class="dropdown-item" id="voronoi-option">Voronoi Hive</a>
-              <a class="dropdown-item" id="random-option">Random Generator</a>
+              <a class="dropdown-item" id="random-option">Random</a>
             </div>
           </li>
-          <input class="form-control mr-sm-2" id="seed" type="search" placeholder="Seed" aria-label="Seed">
+          <span class="navbar-text mr-2">Seed</span>
+          <input class="form-control mr-sm-2 w-25" id="seed" type="search" placeholder="random" aria-label="Seed">
+          <button class="btn btn-outline-success my-2 my-sm-0" type="submit" id="refresh">Refresh</button>
         </ul>
       </div>
       <a class="github-button" href="https://github.com/klangner/mapgen.rs" data-icon="octicon-star"
diff --git a/demo/www/index.js b/demo/www/index.js
index 6cef284..641b368 100644
--- a/demo/www/index.js
+++ b/demo/www/index.js
@@ -30,55 +30,53 @@ function get_seed() {
     return Date.now();
 }
 
+
+function setGenerator(e) {
+    document.getElementById("generatorDropdown").innerHTML = e.target.innerText;
+}
+
 // Map generators
-function newCellularAutomata() {
-    world = World.new_cellular_automata(GRID_COLS, GRID_ROWS, get_seed());
+function refreshMap() {
+    var generator_name = document.getElementById("generatorDropdown").innerHTML;
+
+    switch(generator_name){
+        case "Cellular Automata":
+            world = World.new_cellular_automata(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "Simple Rooms":
+            world = World.new_simple_rooms(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "BSP Rooms":
+            world = World.new_bsp_rooms(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "BSP Interior":
+            world = World.new_bsp_interior(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "Drunkard Walk":
+            world = World.new_drunkard(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "Maze":
+            world = World.new_maze(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        case "Voronoi Hive":
+            world = World.new_voronoi(GRID_COLS, GRID_ROWS, get_seed());
+            break;
+        
+        default:
+            world = World.new_random(GRID_COLS, GRID_ROWS, get_seed());
+    }
+
     requestAnimationFrame(renderLoop);
 }
 
-function newSimpleRooms() {
-    var seed = Date.now();
-    world = World.new_simple_rooms(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newBspInterior() {
-    var seed = Date.now();
-    world = World.new_bsp_interior(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newDrunkard() {
-    var seed = Date.now();
-    world = World.new_drunkard(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newBspRooms() {
-    var seed = Date.now();
-    world = World.new_bsp_rooms(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newMaze() {
-    var seed = Date.now();
-    world = World.new_maze(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newVoronoi() {
-    var seed = Date.now();
-    world = World.new_voronoi(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-function newRandomGen() {
-    var seed = Date.now();
-    world = World.new_random(GRID_COLS, GRID_ROWS, get_seed());
-    requestAnimationFrame(renderLoop);
-}
-
-const renderLoop = () => {
+// Main loop
+function renderLoop() {
     // universe.tick();
     drawCells();
     requestAnimationFrame(renderLoop);
@@ -160,14 +158,16 @@ const drawCells = () => {
     draw_tile(ctx, exit.row(), exit.col(), "exit");
 };
 
-newRandomGen();
-
 // Connect UI element
-document.getElementById('cellular-automata-option').addEventListener('click', newCellularAutomata);
-document.getElementById('simple-rooms-option').addEventListener('click', newSimpleRooms);
-document.getElementById('bsp-rooms-option').addEventListener('click', newBspRooms);
-document.getElementById('drunkard-option').addEventListener('click', newDrunkard);
-document.getElementById('bsp-interior-option').addEventListener('click', newBspInterior);
-document.getElementById('maze-option').addEventListener('click', newMaze);
-document.getElementById('voronoi-option').addEventListener('click', newVoronoi);
-document.getElementById('random-option').addEventListener('click', newRandomGen);
+document.getElementById('cellular-automata-option').addEventListener('click', setGenerator);
+document.getElementById('simple-rooms-option').addEventListener('click', setGenerator);
+document.getElementById('bsp-rooms-option').addEventListener('click', setGenerator);
+document.getElementById('drunkard-option').addEventListener('click', setGenerator);
+document.getElementById('bsp-interior-option').addEventListener('click', setGenerator);
+document.getElementById('maze-option').addEventListener('click', setGenerator);
+document.getElementById('voronoi-option').addEventListener('click', setGenerator);
+document.getElementById('random-option').addEventListener('click', setGenerator);
+
+document.getElementById('refresh').addEventListener('click', refreshMap);
+
+refreshMap();
\ No newline at end of file