Update app.js

@@ -102,6 +102,7 @@ async function handleEvent(event) {
         let jsonResponse = JSON.stringify(JSON.parse(body), null, '  ');
         jsonResponse=jsonResponse.toString()
         console.log(jsonResponse);
+        text='';
         while(jsonResponse.indexOf('text')!=-1)
         {
           jsonResponse=jsonResponse.substring(jsonResponse.indexOf('text')+5);