title: String parameter passing in jenkins pipeline
body: <p>I am developing a pipeline where in when triggered it should display the parameters and below is the code</p>
  
  <pre><code>node {
  
  stage('preparation')  {
                 timeout(time:15, unit:'MINUTES') {
      id: 'userInput', message: 'preparation',
                      parameters: [
                                  [$class: 'TextParameterDefinition', defaultValue: 'cicd', description: 'dev env', name: 'DEV_PROJECT'],
                                 [$class: 'TextParameterDefinition', defaultValue: 'test', description: 'stage env', name: 'STAGE_PROJECT'],
                                 [$class: 'TextParameterDefinition', defaultValue: 'jboss', description: 'Image Name', name: 'IMAGE_NAME'],
                               ] )
  
                         input message: "Is the PARAMETERS(can be visible on leftside) are correctly set for deployment?", ok: "Promote" }
  echo "${DEV_PROJECT}"
  echo "${STAGE_PROJECT}"
  echo "${IMAGE_NAME}"
  }
  </code></pre>
  
  <p>When i do echo its not populating the values of user input.<br>
  Iam getting below error. My requirement is the user can input the DEV_PROJECT,STAGE_PROJECT and IMAGE_NAME and the values entered by him should be used in the pipeline scripts down the line in build and deploy stages.Iam getting below error</p>
  
  <pre><code>groovy.lang.MissingPropertyException: No such property: DEV_PROJECT for class: groovy.lang.Binding
      at groovy.lang.Binding.getVariable(Binding.java:63)
      at org.jenkinsci.plugins.scriptsecurity.sandbox.groovy.SandboxInterceptor.onGetProperty(SandboxInterceptor.java:242)
      at org.kohsuke.groovy.sandbox.impl.Checker$6.call(Checker.java:284)
      at org.kohsuke.groovy.sandbox.impl.Checker.checkedGetProperty(Checker.java:288)
  </code></pre>
  
  <p>could anyone let me know how to proceed?</p>