The simplest way to make multiple selections in the field is to just connect the values together. So let's say you have a list box like this:
Fruit
-----
Apple
Mango
Orange
Pumpkin
Watermellon
And when they click a button, you want to select Mango, Orange and Pumpkin. Well, why those three? In this case, it's because we want to select all of the orange fruit. Well, that suggests that we should have another field, "Color". So we add the Color field. Now when we click on "Orange", those three fruits will be "selected".
Frankly, I don't think I've ever used a button to make selections in any of my applications. I just make other fields.
That said, buttons are not particularly difficult.
If you don't have version 9, you'll need to write a macro (tools -> edit module) to do the work. Peter was giving you an example of the main code in such a macro, though I wouldn't personally code it that way, so let's go from scratch. First, you'll need some data, so create a new file, and add this to the bottom of the script:
LOAD * INLINE [
Fruit
Apple
Mango
Orange
Pumpkin
Watermellon
];
Run the script and add a list box for Fruit. Then do tools -> edit module to create a macro. Cut and paste the following code:
sub OrangeFruit
set fruit = activedocument.fields("Fruit") ' fruit now refers to field Fruit
fruit.select "Orange" ' clears all selections in Fruit and selects Orange
fruit.toggleselect "Mango" ' selects Mango
fruit.toggleselect "Pumpkin" ' selects Pumpkin
end sub
Click OK to get back to your document. Add a button. In the button properties, on the General tab, under function, select Macro. Go to the macro tab, and select OrangeFruit as your macro name. Click OK. Pressing the button should now select the orange fruit.
Now if you click on the button, it should select the orange fruit.
If you have version 9, let's try it the version 9 way. Add a button. Under the properties for the button, go to the actions tab and click add. Click on selection and select in field. Hit OK. type in Fruit for the field and Mango for the search string. Then add -> selection -> toggle select -> Fruit -> Orange. Then add -> selection -> toggle select -> Fruit -> Pumpkin. Click on OK. Pressing the button should now select the orange fruit.
For reference, here is a sample file with both buttons as well as a Color field.
