diff --git a/main.lua b/main.lua
index cbf8a17..b91a6b3 100644
--- a/main.lua
+++ b/main.lua
@@ -19,7 +19,6 @@ dofile("timecore.lua")
 dofile("wordclock.lua")
 dofile("displayword.lua")
 
-timezoneoffset=1
 ledPin=4
 -- Color is defined as GREEN, RED, BLUE
 color=string.char(0,0,250)
@@ -81,5 +80,10 @@ tmr.alarm(1, 15000, 1 ,function()
         end
      end
  end
+ -- cleanup
+ ledBuf=nil
+ words=nil
+ time=nil
+ collectgarbage()
 end)
 
diff --git a/webserver.lua b/webserver.lua
index 4ee3997..ef241b9 100644
--- a/webserver.lua
+++ b/webserver.lua
@@ -4,6 +4,7 @@ configFile="config.lua"
 
 
 function sendWebPage(conn,answertype)
+  collectgarbage()
   if (ssid == nil) then
     ssid="Not set"
   end
@@ -14,20 +15,42 @@ function sendWebPage(conn,answertype)
     timezoneoffset=1
   end
   buf="HTTP/1.1 200 OK\nServer: NodeMCU\nContent-Type: text/html\n\n"
-  buf = buf .. "<html><body>\n"
-  buf = buf .. "<h1>Welcome to the WordClock</h1>"
-  buf = buf.. "<h2>Configuration</h2><form action=\"\" method=\"POST\">"
-  buf = buf.. "<label for=\"ssid\">WIFI-SSID: <input id=\"ssid\" name=\"ssid\" value=\"" .. ssid .. "\"></label><br/>"
-  buf = buf.. "<label for=\"password\">Password: <input id=\"password\" name=\"password\"></label><br/>"
-  buf = buf.. "<label for=\"sntpserver\">SNTP Server: <input id=\"sntpserver\" name=\"sntpserver\" value=\"" .. sntpserverhostname .. "\"></label><br/>"
-  buf = buf.. "<label for=\"timezoneoffset\">Offset from UTC: <input id=\"timezoneoffset\" name=\"timezoneoffset\" value=\"" .. timezoneoffset .. "\"></label><br/>"
-  buf = buf.. "<input type=\"submit\" value=\"Configure Clock\"></form>"
-  if answertype>1 then
-   buf = buf .. "<h2>New configuration saved</h2\n>"
+  if (node.heap() < 10000) then
+  buf = buf .. "<h1>Busy, please come later again</h1>"
+  else
+  buf = buf .. "<html>"
+  buf = buf .. "<head><title>WordClock Setup Page</title>"
+  if (bennyHack ~= nil) then
+  buf = buf .. "<style type=\"text/css\"> #table-6 { width: 100% border: 1px solid #B0B0B0; } "
+  buf = buf .. "#table-6 tbody { margin: 0; padding: 0; border: 0; outline: 0; font-size: 100%; vertical-align: baseline; background: transparent; } #table-6 thead { text-align: left; } "
+  buf = buf .. "#table-6 thead th { background: -moz-linear-gradient(top, #F0F0F0 0, #DBDBDB 100%);"
+  buf = buf .. " background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #F0F0F0), color-stop(100%, #DBDBDB)); "
+  buf = buf .. "filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#F0F0F0', endColorstr='#DBDBDB', GradientType=0); border: 1px solid #B0B0B0; color: #444; font-size: 16px; font-weight: bold; padding: 3px 10px; } "
+  buf = buf .. "#table-6 td { padding: 3px 10px; }"
+  buf = buf .. " #table-6 tr:nth-child(even) { background: #F2F2F2; } </style>"
+  end
+  buf = buf .. "</head><body>\n"
+  buf = buf .. "<h1>Welcome to the WordClock</h1>Please note that all settings are mandatory<br /><br />"
+  buf = buf .."<form action=\"\" method=\"POST\">"
+  buf = buf .."<table id=\"table-6\">"
+  buf = buf .."<tr><th>WIFI-SSID</b></th><td><input id=\"ssid\" name=\"ssid\" value=\"" .. ssid .. "\"></td><td>SSID of the wireless network</td></tr>"
+  buf = buf .."<tr><th>WIFI-Password</th><td><input id=\"password\" name=\"password\"></td><td>Password of the wireless network</td></tr>"
+  buf = buf .."<tr><th>SNTP Server</th><td><input id=\"sntpserver\" name=\"sntpserver\" value=\"" .. sntpserverhostname .. "\"></td><td>Server to sync the time with. Only one ntp server is allowed.</tr>"
+  buf = buf .."<tr><th>Offset to UTC time</th><td><input id=\"timezoneoffset\" name=\"timezoneoffset\" value=\"" .. timezoneoffset .. "\"></td><td>Define the offset to UTC time in hours. For example +1 hour for Germany</tr>"
+  buf = buf .. "<tr><td colspan=\"3\"><div align=\"center\"><input type=\"submit\" value=\"Save Configuration\" onclick=\"this.value='Submitting ..';this.disabled='disabled'; this.form.submit();\"></div></td></tr>"
+  buf = buf .."</table></form>"
+  if answertype==2 then
+   buf = buf .. "<h2><font color=\"green\">New configuration saved</font></h2\n>"
+  elseif answertype==3 then
+   buf = buf .. "<h2><font color=\"red\">ERROR</font></h2\n>"
+  elseif answertype==4 then
+   buf = buf .. "<h2><font color=\"orange\">Not all parameters set</font></h2\n>"
   end 
   buf = buf .. "\n</body></html>"
+  end
   conn:send(buf)
   buf=nil
+  collectgarbage()
 end
 
 function startWebServer()
@@ -51,21 +74,23 @@ function startWebServer()
      end
      postRequestData=nil
      if ((_POST.ssid~=nil) and (_POST.password~=nil) and (_POST.sntpserver~=nil) and (_POST.timezoneoffset~=nil)) then
+
       -- Safe configuration:
-      file.remove(configFile)
-      file.open(configFile, "w+")
-      w = file.writeline
-      w("-- Config")
-      w("wifi.sta.config(\"" .. _POST.ssid .. "\",\"" .. _POST.password .. "\")")
-      w("sntpserverhostname=\"" .. _POST.sntpserver .. "\"")
-      w("timezoneoffset=\"" .. _POST.timezoneoffset .. "\"")
+      file.remove(configFile .. ".new")
+      file.open(configFile.. ".new", "w")
+      file.write("-- Config\n" .. "wifi.sta.config(\"" .. _POST.ssid .. "\",\"" .. _POST.password .. "\")\n" .. "sntpserverhostname=\"" .. _POST.sntpserver .. "\"\n" .. "timezoneoffset=\"" .. _POST.timezoneoffset .. "\"\n")
       file.close()
-      sendWebPage(conn,2)
+      file.remove(configFile)
+      if (file.rename(configFile .. ".new", configFile)) then
+        sendWebPage(conn,2) -- success
+      else
+        sendWebPage(conn,3) -- error
+      end
      else
       ssid, password, bssid_set, bssid = wifi.sta.getconfig()
-      sendWebPage(conn,1)
-      conn:on("sent", function(conn) conn:close() end)
+      sendWebPage(conn,4) -- not all parameter set
      end
+     conn:on("sent", function(conn) conn:close() end)
     else
      --here is code, if the connection is not from a webbrowser, i.e. telnet or nc
      global_c=conn
@@ -82,7 +107,7 @@ function startWebServer()
        node.output(nil)
        global_c=nil
      end)
-     print("Welcome to WS2812Clock")
+     print("Welcome to Word Clock")
      
     end
    end

WIFI-SSID		SSID of the wireless network
WIFI-Password		Password of the wireless network
SNTP Server		Server to sync the time with. Only one ntp server is allowed.
Offset to UTC time		Define the offset to UTC time in hours. For example +1 hour for Germany