It's not really clear what the situation is, and what you want to achieve.

Do you mean that you only want to submit the file if a certain state is selected (in a drop-down, I presume)?

You can use the validate event of the dropdown to check the current

selected value and then set the required property of the fields in

question. So, for example, if the tax exemption fields is called "Tax

Exemption" and you want to make it required if "Alaska" or "Ohio" are

selected, you can use something like this:

this.getField("Tax Exemption").required = (event.value == "Alaska" ||

event.value == "Ohio");

When you say "form" are you talking about an entire file, a part of a file,

a form field?

So how you expect it to work? Let's say the user selects "AK" in the

drop-down. What should happen then?

This is not so easy to implement. You say that the other form will "come

up". That means that the script needs to know where that form is located.

So that means the documents always have to be in the same location on each

computer, or always be in the same relative location to one another.

Another option is to set all the files in a portfolio, which might make it

simpler.

I would consider another approach, like presenting the user with a message

saying they have to fill in the other file, or merging the two documents to

a single PDF, and enabling/disabling the form fields of the exemption form

based on the state selection.

Yes, it will be very similar to that one. Although, I would suggest splitting the two parts of the code. Let's say you want to make the fields "Text1" and "Text2" visible if any of those states are chosen, or invisible otherwise.

You can use something like this:

var isTaxExemption  = (event.value == "AR" || event.value == "CA" || event.value == "IL" || event.value == "MI" || event.value == "PA");

if (isTaxExemption==true) {

      this.getField("Text1").display = display.visible;

      this.getField("Text2").display = display.visible;

} else {

      this.getField("Text1").display = display.hidden;

      this.getField("Text1").value = "";

      this.getField("Text2").display = display.hidden;

      this.getField("Text2").value = "";

}