Re: How to keep form fields blank with calculated fields

So you're saying that a result of zero is valid, and that you want to suppress a result of zero only if the LengthRisersToday field is blank? If so, the script could be changed to:

var s1 = getField("LengthRisersToday.1").valueAsString;

var v2 = +getField("LengthRisersToDate.0").value;

if (s1) {

    var sum = +s1 + v2;

    event.value = sum;

} else {

    event.value = "";

}