Adobe Java Script Expressions

Question

Question #1    I have a check box field and two data fields containing only letters no numbers in an Adobe Acrobat Form. I would like to have a java script expression that if the Check box 1 field is checked, the contents of Data Field 1 will be automatically entered into Data Field 2 .
Please provide script and below are the 3 fields.
Check box 1 field: Checked
Data Field 1
Data Field 2
Question #2    I have a field labeled Full Address that I am trying to get the following fields to populate from. The problem in my expression is when there is no Suite then there is an extra comma still showing.
Please provide script.
Sample of my script below.
event.value = this.getField("Merchant_Addr1").value.concat( ", ", this.getField("Merchant_Addr2").value) + ", " + this.getField("Merchant_City").value + ", " + this.getField("Merchant_State").value + "  " + this.getField(" Merchant_Zip").value;
This is what displays if no Suite is in Address (Two commas after the word Drive: 23175 La King Drive, , Irvine, CA  92656
Data Field Street Address
Data Field Suite (If empty then don't show comma)
Data Field City
Data Field State
Data Field Zip

Answer 1

For question number 2, I would use a reusable document level function to combine 3 fields a time and adjust for null field values.
// 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;
var Addr1 = this.getField("Merchant_Addr1").valueAsString;
var Addr2 = this.getField("Merchant_Addr2").valueAsString;
var City = this.getField("Merchant_City").valueAsString; 
var State = this.getField("Merchant_State").valueAsString;
var Zip = this.getField(" Merchant_Zip").valueAsString;
var s = fillin(Addr1, Addr2, City, ", ");
var s = fillin(s, State, "", ", ");
event.value = fillin(s, Zip, "", "  ");
Or the custom calculation script could be reduced to:
// custom calculation script;
var Addr1 = this.getField("Merchant_Addr1").valueAsString;
var Addr2 = this.getField("Merchant_Addr2").valueAsString;
var City = this.getField("Merchant_City").valueAsString;
var State = this.getField("Merchant_State").valueAsString;
var Zip = this.getField(" Merchant_Zip").valueAsString;
event.value = fillin(fillin(Addr1, Addr2, fillin(City, State,"", ", "), "", ", "), Zip, "", "  ");
Do not forget the fillin function.