PDF this.resetForm() not working with Prompt on iPhone

Question

I have a button on an Adobe PDF form used to clear all fields. On the Mouse Up trigger on that button, I Run some Javascript. Running the generic reset works just great: this.resetForm(), though a little dangerous for my liking without a prompt. The two different prompt methods I've tried work just fine on Windows 10, but not on my iPhone (running 15.3.1). I've tried two different ways with a prompt as follows:

1)

var nRslt = app.alert("Are you sure you want to clear this form?", 2, 2, "Reset Form Warning");
if (nRslt == 4) {
    this.resetForm();
} 

This doesn't throw an error, but it doesn't clear the form, either.

2)

if (app.alert({cMsg: "Are you sure you want to clear this form?",cTitle: "Reset Form Warning",nIcon: 2,nType: 2}) == 4) {
this.resetForm();
}

This throws the message: [object Object] with an OK button and doesn't clear the form.