Scripting different for Mac acrobat vs acrobat reader app

Can someone explain to me why this script works in Acrobat on my Mac but not when the PDF is opened in the Acrobat reader app on an iPad? I've also attached the PDF.

var f = this.getField("Power1");

switch(event.value) {

case "Upper Body": f.setItems(["elevated explosive push up", "push pass", "push press", "explosive push up from boxes", "single arm snatch", "battlerope", "MB slam", "MB shot put", "clean and press"]);

break;

case "Lower Body": f.setItems(["box jump", "squat jump", "swing", "single arm snatch", "broad jump", "tuck jump", "plyo jump"]); break;

case "Choose One": f.clearItems();}