Assigning Values to a Field Depending on Other Field

Question

Hi,
I'm creating a survey that is used to capture data on a yearly basis. We are attempting to make the survey as self-validating as possible to minimize workload. One section of the survey asks for a yearly change in the number of people in a program, asking for both the number of people entering the program and the number leaving the program. We need this section to self validate by checking that the number of people in the program at the beginning of the year, plus the number added to it, minus the number leaving it, equals the number of people in the program at the end of the year.
The validation formula for this is easy. The difficult problem is automatically assigning a value to the beginning of year value. We will know what this value is due to collecting a response from the program the previous year. My plan is for this field to self-fill depending on an earlier response to the selection of the program name.
Suppose there is a question earlier in the survey asking for the program name, I'll call it ProgramName. This is a drop down list that must be selected from a list. I need the export value of the drop down list to be the program name they selected. My plan is that for the field later in the survey to fill like this:
switch(ProgramName.value)
     case "Program1":
          currentfield = "1"
     case "Program2":
          currentfield = "2"
     default:
          currentfield = "0"
Unforunately I am very new to writing JavaScript and don't know the syntext to get this result. Any help would be appreciated!
Thanks

Answer 1

What you're proposing is a custom calucalte script for the beginning of year value field that gets set based on the dropdown selection. I'd suggest setting the field value in the validate event of the drop down instead, in which case the code would look like:
// Set the beginning of year field value based on this field's selection
// initialize variable
var begin_num = 0;
switch (event.value) {
case "Program1":
    begin_num = "1";
    break;
case "Program2":
    begin_num = "2";
    break;
case "Program3":
    begin_num = "3";
    break;
// Set be beginning number field value
getField("begin_num").value = begin_num;
Where "begin_num" is the name of the field that will contain the beginning number.