Multiple Text Boxes into One Text Box

Question

I need multiple text boxes to populate into one text box.  I've got it to work with....
a=a + "\n " + (this.getField("Other Current Illnesses 1").value)
However, if the field is blank, it gives me a blank line.   What is the code if the box is "empty" to "skip" that text box?
Here is what I tried, but it takes everything away even if there is something in the textbox:
if (this.getField("Other Current Illnesses 1").value !==null) {a=a + ""} else
a=a + "\n " + (this.getField("Other Current Illnesses 6").value)
Any help?

Answer 1

From the sample forms supplied with the Acrobat distribution CD, you can use the "fillin" function that can process up to 3 fields at one time and automatically adjust for null value fields and add an option separator string;
The document level function:
// Concatenate 3 strings with separators where needed
function fillin(s1, s2, s3, sep) {
Purpose: concatenate up to 3 strings with an optional separator
inputs:
s1: required input string text or empty string
s2: required input string text or empty string
s3: required input string text or empty string
sep: optional separator sting
returns:
sResult concatenated string
// variable to determine how to concatenate the strings
  var test = 0; // all strings null
  var sResult; // re slut string to return
// force any number string to a character string for input variables
  s1 = s1.toString();
  s2 = s2.toString();
  s3 = s3.toString();
  if(sep.toString() == undefined) sep = ''; // if sep is undefined force to null
assign a binary value for each string present 
so the computed value of the strings will indicate which strings are present
when converted to a binary value
  if (s1 != "") test += 1; // string 1 present add binary value: 001
  if (s2 != "") test += 2; // string 2 present add binary value: 010
  if (s3 != "") test += 4; // string 3 present add binary value: 100
  /* return appropriate string combination based on
  calculated test value as a binary value
  switch (test.toString(2)) {
  case "0": // no non-empty strings passed - binary 0
     sResult = "";
  break;
  case "1": // only string 1 present - binary 1
     sResult = s1;  
  break;
  case "10": // only string 2 present - binary 10
     sResult = s2;  
  break;
  case "11": // string 1 and 2 present - binary 10 + 1
     sResult = s1 + sep + s2; 
  break;
  case "100": // only string 3 present - binary 100
     sResult = s3;
  break;
  case "101": // string 1 and 3 - binary 100 + 001
     sResult = s1 + sep + s3; 
  break;
  case "110": // string 2 and 3 - binary 100 + 010
     sResult = s2 + sep + s3; 
  break;
  case "111": // all 3 strings  - binary 100 + 010 + 001
     sResult = s1 + sep + s2 + sep + s3; 
  break;
  default: // any missed combinations
     sResult = "";
  break;
return sResult;
Then a custom calculation field for a full business phone number consisting of 4 fields could be:
// Business telephone number w/country code and extension
function doFullBusinessTelephoneVoice() {
  var cc = this.getField("business.telephone.voice.countrycode"); // country code;
  var ac = this.getField("business.telephone.voice.areacode"); // area code;
  var nu = this.getField("business.telephone.voice.number"); // exhchange and phone number;
  var ex = this.getField("business.telephone.voice.extension"); // internal extension number;
  event.value = fillin(cc.value, ac.value, nu.value, "-"); // first 3 fields;
  event.value = fillin(event.value, ex.value, "", "-"); // combined 3 fields and internal extension;
doFullBusinessTelephoneVoice();
It looks like a lot of code, but it is easy to insert document level scripts into t pdf so the actual coding is not that much. And if one hase multiple fields that requrie multiple input fields, the coding task is even less compared to working out each field.