Clearing NaN error from form fields.

Question

Hey all,
Working with this script I have and I thought my condition should clear the NaN erro but it does not.  Does anyone have a clear for the NaN error that might work better.  Basicully,  all the script does is the person using it puts military time into 2 different areas.  One "On" and one "Off".  The NaN error stays in the field until they person using the form puts in the 2 times.
(function () {
    // Get the field values, as numbers
    var v1 = getField("HoursOFF1").value;
    var v2 = getField("HoursON1").value;
    var v3 = getField("HoursDif1").value;
          var time1 = v1.split(":");
          var time2 = v2.split(":");
          var min1 = time1[0]*60 + time1[1]*1 //
          var min2 = time2[0]*60 + time2[1]*1 ;
    if (v3 !== 0) {
       event.value = ((min1 - min2) / 60);
    } else {
        event.value = "";
If anyone can spot my error it would be much appreciated.  Thanks in advance!

Answer 1

Thanks for the help!  I still had to twik it just a little bit more.  Final code follows:
(function () {
    // Get the field values, as numbers
    var v1 = getField("HoursOFF1").value;
    var v2 = getField("HoursON1").value;
          var time1 = v1.split(":");
          var time2 = v2.split(":");
          var min1 = Number(time1[0])*60 + Number(time1[1])*1 //
          var min2 = Number(time2[0])*60 + Number(time1[1])*1 ;
    if (v1 != 0) {
       event.value = ((min1 - min2) / 60);
    } else {
        event.value = "";