title: then is not a valid attribute name in Angular4
body: <p>In angular 4 i am using below html code</p>
  
  <pre><code>&lt;div *ngIf="s.flow";then Avail else NotAvail&gt;&lt;/div&gt;
  &lt;ng-template #Avail&gt;&lt;td&gt;{{s.flow.oo_status.status_info}}&lt;/td&gt;&lt;/ng-template&gt;
  &lt;ng-template #NotAvail&gt;&lt;td&gt;Will Update&lt;/td&gt;&lt;/ng-template&gt;
  </code></pre>
  
  <p>and i am getting below error</p>
  
  <pre><code>DOMException {message: "Failed to execute 'setAttribute' on 'Element': ';then' is not a valid attribute name.", name: "InvalidCharacterError", code: 5, stack: "Error: Failed to execute 'setAttribute' on 'Elemen…10.144.100.162:3000/polyfills.bundle.js:16036:38)", ngDebugContext: DebugContext_…}
  </code></pre>