Custom Action Ribbon

<CustomAction
  
    Id="SkynetCustomRibbonButton"
    RegistrationId="101"
    RegistrationType="List"
    Location="CommandUI.Ribbon"
    Sequence="5"
    Title="Move Documents">
    <CommandUIExtension>
      <CommandUIDefinitions>
        <CommandUIDefinition Location="Ribbon.Documents.Manage.Controls._children">
          <Button
              Id="Ribbon.Documents.New.SkynetTestButton"
              Alt="Move Documents"
              Sequence="5"
              Command="Skynet_Test_Button"
              Image32by32="http://igrid108:44/SiteAssets/searchserver.ico"
              Image16by16="http://igrid108:44/SiteAssets/searchserver.ico"
              LabelText="Move Documents"
              TemplateAlias="o1" />
        </CommandUIDefinition>
      </CommandUIDefinitions>
      <CommandUIHandlers>
        <CommandUIHandler
          Command="Skynet_Test_Button"
          CommandAction="javascript:alert('SharePoint 2010 Rocks!');" />
      </CommandUIHandlers>
    </CommandUIExtension>
  </CustomAction>
--------------------------------------------------------

 <CustomAction
        Id="Comments.Link"
        RegistrationType="List"
        RegistrationId="101"
        Location="EditControlBlock"
        Sequence="350"
        Title="Comments"
        ImageUrl="~/_layouts/1033/IMAGES/CommentsIcon.png"
       Description="Can add comments">
    <UrlAction Url="/_layouts/TR_DMS_DiscussionBoard/TR_DiscussionBoard.aspx?List={ListId}&amp;ID={ItemId}&amp;"/>
  </CustomAction>
----------------------------------------------------------