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Hi,
please help me solve my javascript problem. I'm not a specialist and I can't handle it.

I have in PDF form ex. four number fields. A, B, C, D.
Field A is the entrance. Fields B and C do calculations (ex. A+B+C). Field D=A+B+C this is the result.
Now I want to make an auxiliary field D1.
Script operation. After entering the D1 value, the script substitutes the A value, checks the calculations and the D result, and works until the D = D1 condition is met
Thank you for any tips.

Edit
I came to this solution, but the result is always 1 too big

for (var i=1;this.getField("D1").value!=this.getField("D").value;i++){
this.getField("D").value=this.getField("A").value+this.getField("B").value+this.getField("C").value
this.getField("A").value=this.getField("A").value+1
};