Index: /src/django_gheat/wlheatmap/static/heatmap_extensions.js
===================================================================
--- /src/django_gheat/wlheatmap/static/heatmap_extensions.js	(revision 9577)
+++ /src/django_gheat/wlheatmap/static/heatmap_extensions.js	(revision 9578)
@@ -58,4 +58,8 @@
       $("#sig_value").text("All AccessPoints Signal Strength: " + min + " - " + max);
       $("#signallayer font").text("All AccessPoints Signal: " + min + " - " + max);
+  };
+
+  function update_sig_slider(min,max) {
+      $("#select_sig_value").text("Signal Strength: " + min + " - " + max);
   };
 
@@ -76,4 +80,14 @@
     },
   });
+  $("#select_sig_slider").slider({
+    range: true,
+    min: 0,
+    max: 100,
+    values: [0,100],
+    // while sliding, it changes the text above the slider to show the values realtime
+    slide: function(event, sig){
+      update_sig_slider(sig.values[0], sig.values[1]);
+    },
+  });
 
 
@@ -84,4 +98,7 @@
     signallayer[0].redraw();
     update_slider(min,max);
+
+    $("#select_sig_slider").slider( "option", "values", [min,max] );
+    update_sig_slider(min,max);
   };
 
@@ -323,7 +340,19 @@
 
     // some checks if values are correct, and adding them to parts of the link
-    if (user != ''){user='&meetrondje__gebruiker__naam='+user;}
-    if (dataset != ''){dataset='&meetrondje__naam='+dataset;} 
-    if (wlnode != ''){wlnode='&accespoint__ssid='+wlnode;}
+    if (user == 'all') {
+      user = '';
+    } else {
+      user='&meetrondje__gebruiker__naam='+user;
+    }
+    if (dataset == 'all') {
+      dataset = '';
+    } else {
+      dataset='&meetrondje__naam='+dataset;
+    }
+    if (wlnode == 'all'){
+      wlnode='';
+    } else {
+      wlnode='&accespoint__ssid='+wlnode;
+    }
     if (start_date && end_date){
       sd_d=start_date.substr(0,2);
@@ -352,8 +381,16 @@
       end_date='&meetrondje__datum__lte=' + ed_y +'-'+ ed_m +'-'+ ed_d;
     }
-    if (colour != 'NaN,NaN,NaN'){colour=colour;} 
-    else {colour = Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256)+','+Math.floor(Math.random()*256);}
-    if (lname != ''){lname=lname;} 
-    else {lname = 'Custom Filter';}
+    if (colour != 'NaN,NaN,NaN'){
+      colour=colour;
+    } else {
+      colour = Math.floor(Math.random()*256)+','+Math.floor (Math.random()*256)+','+Math.floor(Math.random()*256);
+    }
+    if (lname == ''){
+      lname= 'Custom Filter';
+    }
+
+    var min = $("#select_sig_slider").slider("values")[0];
+    var max = $("#select_sig_slider").slider("values")[1];
+    signal = '&signaal__gte=' + min + '&signaal__lte=' + max;
 
     // setting layer
@@ -361,5 +398,5 @@
       initialize: function(name, options) {
         var url = [
-          "tile/${z}/${x},${y}.png?&colour=" + colour + user + dataset + wlnode + start_date + end_date 
+          "tile/${z}/${x},${y}.png?colour=" + colour + user + dataset + wlnode + start_date + end_date + signal
         ];
         options = OpenLayers.Util.extend({ numZoomLevels: 21 }, options);
Index: /src/django_gheat/wlheatmap/templates/home.html
===================================================================
--- /src/django_gheat/wlheatmap/templates/home.html	(revision 9577)
+++ /src/django_gheat/wlheatmap/templates/home.html	(revision 9578)
@@ -43,4 +43,8 @@
           <select id="select_dataset" style="width:104px"></select> Dataset<br />
           <select id="select_node" style="width:104px"></select> Node<br />
+          <font id='select_sig_value'>Signal strength: 0 - 100</font>
+          <div id="select_sig_slider">
+            <div id="select_sig_slider"></div>
+          </div>
           <input type="text" id="lname" name="lname" size="10"/> Filtername<br /><br />
           <input type="text" id="colour" name="colour"/> Colour<br /><br />