diff --git a/client/bower.json b/client/bower.json
index ee54d8c..19d429d 100644
--- a/client/bower.json
+++ b/client/bower.json
@@ -16,6 +16,7 @@
     "tests"
   ],
   "dependencies": {
-    "vis": "~3.11.0"
+    "vis": "~3.11.0",
+    "jquery": "~2.1.3"
   }
 }
diff --git a/client/index.html b/client/index.html
index 04888cd..a08aa58 100644
--- a/client/index.html
+++ b/client/index.html
@@ -4,9 +4,10 @@
     <title>Pert</title>
     <link rel="stylesheet" href="bower_components/vis/dist/vis.min.css">
     <style>
+      body { height: 100%; }
       #pert {
-        width: 400px;
-        height: 400px;
+        height: 600px;
+        width: 100%;
         border: 1px solid lightgray;
       }
     </style>
diff --git a/src/pert-cli.coffee b/src/pert-cli.coffee
index 98afe3a..a1c4ed2 100755
--- a/src/pert-cli.coffee
+++ b/src/pert-cli.coffee
@@ -42,7 +42,8 @@ cli
   .command 'graph <file>'
   .description 'serve HTTP GUI with pert graph of given JSON document'
   .alias 'g'
-  .action (file) ->
+  .option '-r, --read-only', 'disallow data editing'
+  .action (file,options) ->
     didSomething = yes
     fs.readFile file, (error,content) ->
       if error then err error
@@ -52,6 +53,9 @@ cli
         app = express()
         app.use express.static 'client'
         app.get '/data', (req,res) -> res.json data
+        if !options.readOnly then app.post '/data', (req,res) ->
+          data = req.body
+          pert.setData(data).calculate()
         app.listen 3000
         console.log chalk.green('Started Web Server'), 'on port', chalk.bold(3000)
 
diff --git a/src/pert-ui.coffee b/src/pert-ui.coffee
index 9f5ef97..4f45258 100644
--- a/src/pert-ui.coffee
+++ b/src/pert-ui.coffee
@@ -1,6 +1,10 @@
-$.get 'data', (data) ->
-  console.log data
-  i = 0
+$.get 'data', (d) ->
+  # Serve the server data
+  list = d
+  console.log list
+  buildGraph list
+
+buildGraph = (data) ->
   nodes = data.days.map (x) -> {id: x, label: ""+x}
   connections = []
   data.activities.forEach (x) ->
@@ -8,10 +12,17 @@ $.get 'data', (data) ->
       from: x.startDay, to: x.endDay
       label: x.id+" ("+(if x.permittedDelay > 0 then x.duration+"/"+(x.duration+x.permittedDelay) else x.duration)+")"
     if x.permittedDelay > 0
-      connections.push from: x.endDay, to: x.endDay+x.permittedDelay, color: 'green', label: "("+x.permittedDelay+")"
+      connections.push
+        from: x.endDay
+        to: x.endDay+x.permittedDelay
+        color: 'green'
+        label: x.id+" ("+x.permittedDelay+")"
   console.log nodes
   console.log connections
-  options =
-    edges:
-      style: 'arrow'
-  network = new vis.Network (document.getElementById 'pert'), { nodes: nodes, edges: connections }, options
+  if network
+    network.setData { nodes: nodes, edges: edges }
+  else
+    options =
+      edges:
+        style: 'arrow'
+    network = new vis.Network (document.getElementById 'pert'), { nodes: nodes, edges: connections }, options
diff --git a/src/pert.coffee b/src/pert.coffee
index fa30383..867a34b 100755
--- a/src/pert.coffee
+++ b/src/pert.coffee
@@ -57,8 +57,14 @@ module.exports = class Pert
       if day is d then return
     @days.push day
 
-  calculate: (options) ->
-    @calculateEndDay @toActivity @highestID()
-    results = activities: @list, days: @days
-    if options?.json then JSON.stringify results else results 
+  setData: (data) ->
+    @list = data
+    return @
 
+  calculate: (options) ->
+    h = @highestID()
+    @list.forEach (x) =>
+      @log '('+x.id+'/'+h+')'
+      @calculateEndDay x
+    results = activities: @list, days: @days
+    if options?.json then JSON.stringify results else results