Calculate a field if box is checked

Question

Hi,
In one of the forms, I am trying to calculate a field value if a box is checked. For aesthetic reason, there are two checkbox field  (Yes/No) with the same field name "CT_Looped" but with different export value - Yes and No. Such that if someone checks Yes, they cant check no and vice versa.
I have the following code in the custom script for the field, which is part of a bigger code:
var DD4 = +getField("PT").value;
var DD3 = +getField("CT").value;
var KW1 = +getField("KWH 1").value;
if (this.getField (CT_Looped).value == "Yes") {  //if the field is checked with an export value Yes
                         event.value = (DD3 * DD4* KW1)/2;}
                else{
event.value = DD3 * DD4* KW1;}
What I am trying to do is if the CT_looped "Yes" checkbox is checked, then field calculates the value as DD3 * DD4* KW1)/2. If its not checked or if the "No" checkbox is checked, then it performs DD3 * DD4* KW1. If neither are checked, then default value of the field is just DD3 * DD4* KW1.
When I check/Uncheck the boxes, nothing happens. Can someone help?

Answer 1

Hi Michael,
thanks! that worked. I have one more question. It's part of a bigger code. each part works separately just fine but together it doesnt.
this is what I am trying to do:
if DD4>0, then if the CT_Looped box is checked, then it should perform  (DD3 * DD4* KW1)/2 otherwise perform DD3 * DD4* KW1.
so for example, DD1 =1, DD3 =100,DD4 =2, KW1 = 1, qty = 1, Auto = drop down with (0, .5,2, 4)
then if i check the box, the value should be 100, otherwise 200, but with the code i created below, if i check the box, the field is always 200 instead of 100. Rest everything works. If i change the Auto ratio from 0 to 2, it becomes 400 as expected. If DD4<0, then if i change qty, the change is reflected as expected. I just cant seem to get the right order of code in which the logic should work correctly.
Any advice? tips?
code is below:
var DD1 = +getField("Factor").value;
var DD4 = +getField("PT").value;
var DD3 = +getField("PT_2").value;
var KW1 = +getField("KWH 1").value;
var qty = +getField("qty").value;
var Auto = +getField("Auto").value;
if (DD4>0){
if (this.getField ("CT_Looped").value == "Yes") { 
event.value = (DD3 * DD4* KW1)/2;}
                                                else {
event.value = DD3 * DD4* KW1;}
if (Auto>0){
event.value = DD3 * DD4* KW1* Auto;}
                                                else{
event.value = DD3 * DD4* KW1;}
else if( ctqty > 1){
event.value = DD3 * DD1* KW1 ; }
else{
event.value = DD3 * KW1;