Help with a form calculation

[Craig26160076pl76]

Hi all. I was just wondering whether someone could assist with a form I have created in Adobe.  I have a form which has to two columns which store numbers used for a progressive calculation. Doing the simple addition calulation is fine, but I dont want the progressive total to show up in all the rows where there is no data.  In excel it would be a simple IF formula, where if there is no data, it doesnt calculate.  Here is snapshot below of what I mean.  As you can see, where there is only three truck loads, the entire colums is filled out, with row three repeated all the way to the bottom.  Is there something similar to an IF function in Adobe? I have also attached the form.  Would greatly appreciate your assistance on this.  Thank you

[try67]

Place this code as a doc-level script and then call that function from the custom calculation event of each one of those fields:

function calcProgressiveTonnes() {
	var rowNumber = Number(event.target.name.replace("Progressive TonnesRow", ""));
	if (this.getField("Truck TonnesRow"+rowNumber).valueAsString=="") event.value = "";
	else {
		if (rowNumber==1) event.value = this.getField("Truck TonnesRow"+rowNumber).valueAsString;
		else event.value = Number(this.getField("Truck TonnesRow"+rowNumber).valueAsString)+Number(this.getField("Progressive TonnesRow"+(rowNumber-1)).valueAsString);
	}
}

[Craig26160076pl76]

Hi Mate,  thanks heaps for your reply and assistance.  As a 'very' basic user of Adobe products, I am still on my 'L' plates with Adobe Acrobat Pro. As for 'doc level scripts' and how to implement this javascript, I have no idea.  Is there any chance you would be able to implant that code into the file I originally attached.  Thank you.  Craig

[try67]

Here you go...

[Craig26160076pl76]

Thanks mate. I really appreciate it. The form works great on the computer, however I did try to use it on the IPAD and it didnt work.  Any ideas as to why the formula woudn't work on the IPAD Adobe App?

[Bernd Alheit]

Acrobat Reader doesn't support all JavaScript features.