Simple Javascript Timer

_live_meeting.html.erb

<div class="row">
  <div class="span6">   
    <% if @meeting.started && [email protected]? %>
      <%= content_for :javascripts do %>
        <script>
          var count = <%= @meeting.before_time %>;
          var cost = <%= @meeting.cost %>;
        </script>
      <% end %>
    <div class="live_input">  
      <%= form_for(@meeting) do |f| %>
        <label for="meeting_cost">Cost</label>
        <input id="meeting_cost" name="Cost" readonly="true" value="<%= @meeting.cost %>">    
        <%= f.label :time %>
        <%= f.text_field :before_time, readonly: true %>
        <%= f.submit "Stop meeting", class: "btn btn-large btn-primary" %>
      <% end %>
    </div>  
    <% else %>
      <div>
        <p>
          <% if @meeting.completed? %>
            <%= "This meeting was 
                #{ pluralize(@meeting.after_time, 'minute') } long and cost 
                #{ pluralize(number_to_currency(@meeting.cost, precision: 0), 'dollar') }." 
            %>
          <% else %>
            <%= "This meeting is expected to be 
                #{ pluralize(@meeting.before_time, 'minute') } long and expected to cost 
                #{ pluralize(number_to_currency(@meeting.cost, precision: 0), 'dollar') }." 
            %>          
          <% end%>
        </p>
      </div>
    <% end %>
  </div>
</div>

meeting_before_time.js

$(function() {
  if (($("#meeting_before_time").length > 0) && ($("#meeting_cost").length > 0)) {
    var clock=self.setInterval(function(){timer()}, 1000);
    var seconds = 60;
    count = count-1

    function timer() {
      seconds = seconds-1;
      if (seconds < 1) {
        seconds = 60;
        count=count-1;
        if (count <= 1) {
          clearInterval(clock);
          $("#meeting_before_time").val("END")
          return;
        }
      }

      if (seconds < 10) {
        $("#meeting_before_time").val(count+ 
          " : " + "0" + seconds);
      } else { 
        $("#meeting_before_time").val(parseFloat(count).toFixed(0) + 
          " : " + parseFloat(seconds).toFixed(0));
      }  
    }
  }
});

meeting_cost.js

$(function() {
  if (($("#meeting_before_time").length > 0) && ($("#meeting_cost").length > 0)) {
    var running_cost = self.setInterval(function(){meter()}, 1000);
    var starting_cost = 0;
    var cost_per_second = cost/(count*60);

    function meter() {
      starting_cost = starting_cost + cost_per_second
      if (starting_cost >= cost) {
        clearInterval(running_cost);
        $("#meeting_cost").val("SPENT")
        return;
      }
      $("#meeting_cost").val("$" + parseFloat(starting_cost).toFixed(2));
    }
  }
});