adds screenshots of ARN Role and Invocation result

examples/lambda_invoke/README.md

@@ -2,24 +2,62 @@
 
 Our objective is to invoke a Lambda Function from another Lambda Function.
 
-Lambda_A invokes Lambda_B
-with a `payload` containing a single parameter `name:'Alex'`.
-Lambda_B replies "Hello Alex".
+## How?
 
-`Lambda_A`:
-```js
+> Start with something *simple*: the "Hello World" of intra-lambda invocation:
 
-```
+`Lambda_A` invokes `Lambda_B`
+with a `payload` containing a single parameter `name:'Alex'`.  
+`Lambda_B` responds with Payload: `"Hello Alex"`.
+
+![lambda invoke](https://cloud.githubusercontent.com/assets/194400/13526240/ac778494-e1fe-11e5-8462-816a0b85ed3d.jpg)
+
+First create `Lambda_B` which expects a `name` *property*
+on the `event` parameter  
+and responds to request with `"Hello "+event.name`:
 
-`Lambda_B`:
+`Lambda_B`
 ```js
 exports.handler = function(event, context) {
   console.log('Lambda B Received event:', JSON.stringify(event, null, 2));
   context.succeed('Hello ' + event.name);
 };
 ```
+Ensure that you give `Lambda_B` and `Lambda_A` the same role.
+We created a new role `lambdaexecute` which has both `AWSLambdaExecute` *and*
+`AWSLambdaBasicExecutionRole` (*for some reason both were required*):
+
+![lambda-role-for-intra-lambda-execution](https://cloud.githubusercontent.com/assets/194400/13526641/15a146c4-e201-11e5-88c1-c70c9eda2bfb.png)
+
+`Lambda_A`
+```js
+var AWS = require('aws-sdk');
+AWS.config.region = 'eu-west-1';
+var lambda = new AWS.Lambda();
+
+exports.handler = function(event, context) {
+  var params = {
+    FunctionName: 'Lambda_B', // the lambda function we are going to invoke
+    InvocationType: 'RequestResponse',
+    LogType: 'Tail',
+    Payload: '{ "name" : "Alex" }'
+  };
+
+  lambda.invoke(params, function(err, data) {
+    if (err) {
+      context.fail(err);
+    } else {
+      context.succeed('Lambda_B said '+ data.Payload);
+    }
+  })
+};
+```
+Once you have saved both these Lambda functions, Test run `Lambda_A`:
+
+![lambda invoke-lambda_a-execution-result](https://cloud.githubusercontent.com/assets/194400/13526744/ec22a062-e201-11e5-8c7b-6bea3b437bd4.png)
+
 
-## Check the Function we are invoking *Exists*
+## Check the Function we are invoking *Exists* before Invoking
 
 The way we end up writing our functions is to first check
 that the lambda function being invoked actually *exisits*,