Custom calculation script to ignore blank fields

Hello there,

I would love some help in finding out what is not working with my calculation code.

I have 10 fields that I want to add together.  The tricky bit is that the fields data is an smpte code in a hh:mm:ss:ff format so I can't do a standard calculation.

I have the calculation working to subtract one fields value with another (with help previously on here) and I have tweaked the code for this new function.  However the calculation only seems to appear in the required field when I delete the last fields entry - very odd as still includes this deleted data in the calculation?

Not sure how to solve this.

In addition I also need the calculation field to ignore any blank fields if any of the ten fields don't have any value in.

Appreciate any guidance.

I have pasted the code below - This is entered into the 'calculation fields' custom calculation script window.  Using Acrobat Pro XI

var t1 = this.getField("P1.Spawn page.P1.Actions page.CUT 1").value;

var t2 = this.getField("P1.Spawn page.P1.Actions page.CUT 2").value;

var t3 = this.getField("P1.Spawn page.P1.Actions page.CUT 3").value;

var t4 = this.getField("P1.Spawn page.P1.Actions page.CUT 4").value;

var t5 = this.getField("P1.Spawn page.P1.Actions page.CUT 5").value;

var t6 = this.getField("P1.Spawn page.P1.Actions page.CUT 6").value;

var t7 = this.getField("P1.Spawn page.P1.Actions page.CUT 7").value;

var t8 = this.getField("P1.Spawn page.P1.Actions page.CUT 8").value;

var t9 = this.getField("P1.Spawn page.P1.Actions page.CUT 9").value;

var t10 = this.getField("P1.Spawn page.P1.Actions page.CUT 10").value;

if (t1 != 0 && t2 != 0 && t3 != 0 && t4 != 0 && t5 != 0 && t6 != 0 && t7 != 0 && t8 != 0 && t9 != 0 && t10 != 0) {

  event.value = frames_to_timecode (timecode_to_frames(t1) + timecode_to_frames(t2) + timecode_to_frames(t3) + timecode_to_frames(t4) + timecode_to_frames(t5) + timecode_to_frames(t6) + timecode_to_frames(t7) + timecode_to_frames(t8) + timecode_to_frames(t9) + timecode_to_frames(t10));

}

else {

    event.value = "";

}

I also have the following (again thanks to assistance on here) pasted into the document level scripts to work out the smpte code format.

var framerate = 24

function timecode_set_framerate(rate) {

  framerate = rate;

}

function timecode_get_framerate() {

  return framerate;

}

function timecode_to_frames(timecode) {

    var a = timecode.split(':');

    return ((Number(a[0])*3600 + Number(a[1])*60 + Number(a[2]))*framerate + Number(a[3]));

}

function frames_to_timecode(frames) {

  return util.printf("%02d:%02d:%02d:%02d",

    Math.floor(frames / (3600 * framerate)),

    Math.floor((frames / (60 * framerate)) % 60),

    Math.floor((frames / framerate) % 60),

    frames % framerate);

}