I'm following the creating a page layout in this example
http://blog.beckybertram.com/Lists/Posts/Post.aspx?ID=71
It adds a page layout using this xml,
<File Path="masterpage\MyCustomPageLayout.aspx" Url="MyCustomPageLayout.aspx" Type="GhostableInLibrary">
<Property Name="Title" Value="My Custom Page Layout" />
<Property Name="ContentType" Value="$Resources:cmscore,contenttype_pagelayout_name;" />
<Property Name="PublishingPreviewImage" Value="~SiteCollection/_catalogs/masterpage/$Resources:core,Culture;/Preview Images/CustomPageLayout.png, ~SiteCollection/_catalogs/masterpage/$Resources:core,Culture;/Preview Images/CustomPageLayout.png" />
<Property Name="PublishingAssociatedContentType" Value=";#$Resources:cmscore,contenttype_articlepage_name;;#0x010100C568DB52D9D0A14D9B2FDCC96666E9F2007948130EC3DB064584E219954237AF3900242457EFB8B24247815D688C526CD44D;#" />
</File>
I've created my own content type based on the Welcome Page, I want to associate this page layout with, how do I find the GUID of this content type to put in this property <Property Name="PublishingAssociatedContentType" ...
?