User input request

Now we will create a workflow which need some data from user. This is the workflow graph:

And this is the workflow definition:

<?xml version="1.0" encoding="UTF-8"?>
<process-definition xmlns="" name="UserInput">
  <start-state name="start">
    <transition to="PlaceOrder" name="trPlaceOrder"></transition>
  </start-state>
  <task-node name="PlaceOrder">
    <task name="MyTask">
      <assignment actor-id="tazplat"></assignment>
      <controller></controller>
    </task>
    <transition to="CheckAvailability"></transition>
  </task-node>
  <decision name="CheckAvailability" expression="#{(amount&gt;100)?'trNotAvailable':'trAvailable'}">
    <transition to="end" name="trAvailable"></transition>
    <transition to="sendMail" name="trNotAvailable"></transition>
  </decision>
  <mail-node name="sendMail" to="stock@your-domain.com">
    <subject>We need more product</subject>
    <text>There is no product, so we must to buy more units!</text>
    <transition to="end"></transition>
  </mail-node>
  <end-state name="end"></end-state>
</process-definition>

And this is the form for the user input value: