title: Error adding 'data'-tag when calling web-service from PowerShell
body: <p>I have the below web-service request written in Python, but need to convert it to PowerShell in order to deploy it on our production environment.</p>
  
  <p>Somehow I can't seem to get the data-part of the call working (so it will not authenticate me). It it working fine from Python, but what should the syntax be for PowerShell</p>
  
  <pre><code>import requests
  import json
  
  r = requests.post("http://ws.issworld.com/SourceSystem/rest/json/usm/login", 
                             data='''{"userName":"JohnDoe", "password":"xxxxxxxxx"}''', 
                             headers={"Content-type": "application/json"})
  if(not r.ok):
      print("Couldn't login.", str(r.status_code), str(r.headers), str(r.text))
      exit(1)
  </code></pre>
  
  <p>Any pointers will be welcome. I'm a newbie on both PowerShell and web-services.</p>