validate polling_interval format

app/models/project.rb

@@ -3,6 +3,8 @@ class Project < ActiveRecord::Base
   validates_presence_of :name, :path, :scripts, :timeout, :token, :default_ref
+  validates :polling_interval, :format => { :with => /^[1-9]\d{0,7}[s|m|d]$/ }, :unless => Proc.new{|project| project.polling_interval.blank?}
+
   has_many :builds, dependent: :destroy
   validate :repo_present?

app/views/projects/_form.html.haml

@@ -18,10 +18,10 @@
           = f.label :token, "Token (Leave empty to generate random token)"
           = f.text_field :token, class: 'input-xlarge', placeholder: 'xEeFCaDAB89'
         .field
-          = f.label :always_build, "always_build"
+          = f.label :always_build, "Always_build"
           = f.check_box :always_build
         .field
-          = f.label :polling_interval, "polling_interval"
+          = f.label :polling_interval, "Polling_interval"
           = f.text_field :polling_interval
       %fieldset