// Place your application-specific JavaScript functions and classes here
// This file is automatically included by javascript_include_tag :defaults
function add_x(element_id, x){                        
  
  new_val = Number($(element_id).val()) + x;
  
  if (isNaN(new_val) || new_val < 0){
    new_val = 0;
  }
    
  $(element_id).val(new_val);
  draw_green(element_id)
}
        

function draw_green(element_id){
  if ($(element_id).val() > 0){
    $(element_id).addClass('green')
  }else{
    $(element_id).removeClass('green')
  }
  
}
  
function add_one(element_id){
  add_x(element_id, 1)
} 

function sub_one(element_id){
  add_x(element_id, -1)
}