var $extNumber = $('[data-ext-number=wrapper]')
var $extNumberInput = $extNumber.find('[data-ext-number=input]')

$extNumber.on('click','[data-ext-number=minus]',function(){
  var value = $extNumberInput.val()
  value = !isNaN(+value) ? parseInt(+value) : 0
  $extNumberInput.val(value < 1 ? 0 : value - 1)
})

$extNumber.on('click','[data-ext-number=plus]',function(){
  var value = $extNumberInput.val()
  value = !isNaN(+value) ? parseInt(+value) : 0
  $extNumberInput.val(value + 1)
})