OIC - JS - Return boolean status based on ERP result status

Requirement:

From ERP we are getting Import status as 'SUCCEEDED','WARNING','ERROR','CANCELED' and we need to convert it to boolean status like true or false.

JS code:

function returnStatus(result) {

 var inProgress;

  if (['SUCCEEDED','WARNING','ERROR','CANCELED'].indexOf(result)==-1)

  {

  inProgress = "true";

  }

  else

  {

  inProgress="false"

  }

  return inProgress;

}