Below is the test code:

function testError(something) {
   alert("Before outermost try");
   try {
      // ...
      try {
         if (something) {
            alert("Throwing an exception");
            throw "Something went wrong";
         }
         // if no error then we continue
         alert("You didn't want to throw an exception so the execution continues");
      }
      catch(oException) {
         throw oException; // If we don't want to process the erro
                           // we should pass it along
      }
   }
   catch(oException) {
      alert("Got the following expection data: " + oException);
   }
   alert("After outermost try");
}