Calculating Sum - Adding Fee to Most of the Items

[John in Tennessee]

Calculating Sum - additional fee variable

I want to calculate the sum of 29 fields.

There is a $30 base fee that gets added to the sum of the fields.

However, there are two items in the list that do not get charged that additional 'base fee' of $30 (highlighted in the image)

Right now, I am using this simplified field notation:

(Cost1+Cost2+Cost3+Cost4+Cost5+Cost6+Cost7+Cost8+Cost9+Cost10+Cost11+Cost12+Cost13+Cost14+Cost15+Cost16+Cost17+Cost18+Cost19+Cost20+Cost21+Cost22+Cost23+Cost24+Cost25+Cost26+Cost27+Cost28+Cost29+Cost30+30)

What's the best way for me get the correct calculation? 

[try67]

So you want to add the fee if any of the other fields are selected, basically? Do all of these fields have a value, or does the user enter one into them? Does it not also rely on the quantity fields (Cost*Quantity)?

[John in Tennessee]

The fee only gets added to the sum, not to the items indivuidually. When the user enters a value, the cost for that item is set to calculate. Then the sum of all of the individual fields is calculated. Right now, the "Total Permit Fee" field also adds $30 to the calculation (that's for the 'base fee' charged by the department. Hoever, there are two items in the list that should not be assessed that additional $30 fee.

[try67]

I'm trying to understand how it should work practically, though. Say the user entered qty 1 for Gas Safety only. Then the cost for that field is calculated to be 50 (for example). So the total is just 50. That's clear.

But if they enter "1" for Boiler then the cost for that field becomes 30, say. So what's the total now? Isn't it 50+30+30 (the fee because of Boiler) = 110?

There's no way not to apply the fee to these two items, too, unless they are the only ones that are selected...

[John in Tennessee]

"There's no way not to apply the fee to these two items, too, unless they are the only ones that are selected..."

That's the part that I want to fix. If the user only selects one (or both) of the highlighted items, how can I prevent the base fee of $30 from being added to the Total Permit Fee field?

[try67 · Accepted solution]

Try this code as the custom calculation script of the total field:

var total = 0;
var addFee = false;
for (var i=1; i<=30; i++) {
	var cost = Number(this.getField("Cost"+i).valueAsString);
	total+=cost;
	if (cost>0 && i!=1 && i!=24) addFee = true;
}
if (addFee) total+=30;
event.value = total;

[John in Tennessee]

Thank you! It's perfect!

I appreciate your time to provide this solution. I'm definitely a novice when it comes to using java script for calculations.