Simple subtract + calculate discount % (based on checked option)

First, you can use the 'Format' tab to display the Percentage sign and Currency symbols without affecting the computational amount of the displayed field.

The trick to using the discount selected in a calculation is having the 3 check boxes all named the same and then setting the 'Export Value' for each check box to the decimal value for the discount being applied. For 12% use 0.12, for 15% use 0.15 and for 18% use 0.18. This is the value of the check box field. If no check box is selected the export value will be the character string "Off"

With that done, you can create a field to show the amount of the discount being given. Use a text field and set the format to a number and select the appropriate currency symbol. For the calculation, you an select the 'Value is the ___ of the following fields:' and select the field for the check box and the subtotal fields. This method of calculation will treat the string value of "Off" as zero.

Calculating the "TOTAL" will be more complicated, since the discount amount is specified as a positive number and there is no option for subtraction. But you can use the 'Simplified field notation' and enter the following code:
You might want to look over How to do (not so simple) form calculations by Thom Parker for other ideas.

Thanks a lot gkaiseril!

I'm going to try your solution, but in the meantime let me explain what I did so far (before reading your post)..

I have the 3 radio buttons with the same name (DISCOUNT%) but different button value (0.12, 0.15, 0.18),
so far so good...

Then, I've (tried to) make a a script in the DISCOUNT$ field saying:

—————————————

if
this.getField("DISCOUNT%") = 0.12;
then
this.getField("DISCOUNT$") = (SUBTOTAL * 0.12);
else if
this.getField("DISCOUNT%") = 0.15;
then
this.getField("DISCOUNT$") = (SUBTOTAL * 0.15);
else
this.getField("DISCOUNT$") = (SUBTOTAL * 0.18);

—————————————

Am I getting anywhere with this, or am I waaaay off..??

Thanks again!!

OK GREAT I GOT IT WORKING!!

I was making oit way too difficult and wasting lots of time with the script, stubborn as I am!!
Just before going completely nuts I went back to your post and actually followed your instructions,
made PERFECT SENSE and all is fine now... fjew, was I getting sweaty!!

Thanks so much again George!!


Ps. just for my knowledge, would a script like I was messing with have been an option at all??

This is where I gave up:

--------
if(this.getField("DISCOUNT%") = 0.12)
then this.getField("DISCOUNT$") = (SUBTOTAL * 0.12);
else if(this.getField("DISCOUNT%") = 0.15)
then
this.getField("DISCOUNT$") = (SUBTOTAL * 0.15);
else
this.getField("DISCOUNT$") = (SUBTOTAL * 0.18);
--------

I'm just wondering if I was making any sense at all..
Although your solution was so much more sensible & logical!!

I would have just checked to see if the value of the check box is 'Off'. If it is "Off", the the discount rate is zero. The rest is just computing the value.