ajax request success template missing

buildings_controller.rb

  def getgst
    d { 'gets fired' }
    s = Building.get_gst_for_building(params[:buildinginfo])
    d { s.to_s('F') }
    @var = s.to_s('F')

    respond_to do |format|
      format.html { render :text => @var.html_content }
  end

tenants.js.coffee

	$("#tenant_tenantbuildinginfo").change ->
		$.ajax
			url: "/buildings/getgst",
			data: 'buildinginfo' : $(this).val(),
			success: (data) ->
				console.log data
				$("#tenant_gst").val data
			error: (data) ->
			    console.log data
		return false