Return Early Pattern for Functions - help needed

**I have trouble with this challenge. I checked solutions on the forum and everyone seemed to do the same as what I did. Yet when I run the test I get the following error message:

// running tests
abTest(-2,2) should return undefined
abTest(2,-2) should return undefined
// tests completed

Does anyone have any idea what I might do wrong?

Thanks a lot! **

Your code so far

// Setup
function abTest(a, b) {
  // Only change code below this line
  if (a<0 || b<0) {
  return "undefined";
  // Only change code above this line

  return Math.round(Math.pow(Math.sqrt(a) + Math.sqrt(b), 2));

// Change values below to test your code

Your browser information:

User Agent is: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_14_5) AppleWebKit/605.1.15 (KHTML, like Gecko) Version/12.1.1 Safari/605.1.15.

Link to the challenge:

you are returning a string, which is totally different from the data type undefined (note that if a function doesn’t return anything it returns undefined as default - try this too once you are able to use the explicit way)

Ahhhh okay! Thank you so much!!