Formatting Question: Java (?) calculations in forms in Adobe Acrobat

[C5C28]

Hello - thanks for hopefully attempting to answer my question. 

I'm trying to set up formatting/auto functions in fields in forms using Adobe Acrobat calculations. What I am wanting to do is have around 4 - 5 fields in a form which all add up. Pretty simple so far (ie go to properties in the form and add etc). 

However I'm wanting the fields that I enter a number into and then the final "calculator field" in the form to be formatted with an automatic "+" or "-" depending on what is entered. 

Two examples both using 4 fields that I enter data into in the form and one "calculator field:

EXAMPLE 1: 

What I enter: Field 1; "4",  Field 2; "10",  Field 3; "-5",  Field 4; "25", Final "Calculator field"; "34"

What I would like to see in Example 1:  Field 1; "+4",  Field 2; "+10",  Field 3; "-5",  Field 4; "+25", Final "Calculator field"; "+34"

EXAMPLE 2

What I enter: Field 1; "10",  Field 2; "-25",  Field 3; "0",  Field 4; "-5", Final "Calculator field"; "-20"

What I would like to see in Example 1:  Field 1; "+10",  Field 2; "-25",  Field 3; "-",  Field 4; "-5"; Final "Calculator field";  "-20"

In other words I am seeking that a positive number have a "+" in front of it, a negative number have a "-" in front of it and zero result have a "-"/dash in the field. 

My understanding is that the script would need to be entered into the "Custom Calculate script" box in the Properties of the "calculator field". Am I correct? And I understand that that should be in Javascript correct? 

If so, what is the script I need to achieve what I am after? 

Thanks very much and look forward to hearing back with any ideas anyone would care to share. 

Kind regards

Chris

[Nesa Nurani]

Use this code as "Custom Format Script":

if (event.value>0){var cr ="+"}else{var cr=""}AFNumber_Format(0,0,0,0,cr,true)

[Nesa Nurani · Accepted solution]

For 0 add this code also:

if(event.value == 0){event.value = "-";}

[C5C28]

Great thanks very much for your help Nesa. Really appricate you taking the time to respond.

[try67]

It's JavaScript, not Java. Similar names, very different languages.

[C5C28]

thanks - I didn't know that.