Javascript formula Not Working

Hello Everyone.

I was unable to get any of the scripts to work and then the client I was making the form for decided they wanted some changes which required me to start from scratch again.  But I am back to the same problem with this formula.  This is what I put in:
var a = this.getField("Amount3").value;
var b = this.getField("Amount4").value;
var c = this.getField("Item7");
if(c.isBoxChecked(0)){event.value = (a+b)*.06;
}else event.value = "$0.00";

The formula works but when you go to put the amounts in Amount3 and Amount4 Acrobat flashes a message "The value entered does not match the format of the field (Amount7)  

I'm assuming that you want if checkbox is checked tax is calculated?

use this code:

var a = this.getField("Amount3").value;
var b = this.getField("Amount4").value;
var c = this.getField("Enter Checkbox Field Name Here");
if(c.isBoxChecked(0)){event.value = (a+b)*.06;
}else event.value = "$0.00";

Also consider formating your field to number and add currency simbol ( as ls_rbls mention in this post and try67 in your first post) in that case replace "$0.00" with "0"

You didn't have to open new post, you could just ask in your first thread what the problem was with the code and I would gladly help you, also in my code there is *.06 and not *0.6

+++EDITED REPLY  , FIXED AN ERROR IN THE LAST LINE OF THE SCRIPT

Just place the script in the custom calculation script section of the field that will be performing the check. 

Like this:

var a = this.getField("Item3_Amt").value; 
var b = this.getField("Item4_Amt").value; 
var c = this.getField("Dropdown36").valueAsString;

 if(c == "yes") event.value = (a+b)*0.06;
else event.value = 0;


 

Note that 6%  is not calculated with 0.6.

Also, all you need to do to have the empty calculated field display "$0.00" is use the built-in fomat scheam for your numbers.

See slide below: