Modify sitedefinition-> default. aspx:
<% @ Page Language = "C #" Masterpagefile = "~ Masterurl/custom. Master" Inherits = "Microsoft. Sharepoint. webpartpages. webpartpage, Microsoft. Sharepoint, version = 14.0.0.0, culture = neutral, publickeytoken = 71e9bce111e9429c" %> <% @ Register Tagprefix = "SharePoint" Namespace = "Microsoft. Sharepoint. webcontrols" Assembly = "Microsoft. Sharepoint, version = 14.0.0.0, culture = neutral, publickeytoken = 71e9bce111e9429c" %> <% @ Register Tagprefix = "Utilities" Namespace = "Microsoft. Sharepoint. Utilities" Assembly = "Microsoft. Sharepoint, version = 14.0.0.0, culture = neutral, publickeytoken = 71e9bce111e9429c" %> <% @ Register Tagprefix = "Asp" Namespace = "System. Web. UI" Assembly = "System. Web. Extensions, version = 3.5.0.0, culture = neutral, publickeytoken = 31bf3856ad364e35" %> <% @ Register Tagprefix = "Webpartpages" Namespace = "Microsoft. Sharepoint. webpartpages" Assembly = "Microsoft. Sharepoint, version = 14.0.0.0, culture = neutral, publickeytoken = 71e9bce111e9429c" %> <% @ Import Namespace = "Microsoft. SharePoint" %> <% @ Import Namespace = "Microsoft. Sharepoint. applicationpages" %> <% @ Assembly Name = "Microsoft. Web. commandui, version = 14.0.0.0, culture = neutral, publickeytoken = 71e9bce111e9429c" %> < ASP : Content ID = "Content1" Contentplaceholderid = "Placeholdermain" Runat = "Server"> < H1 > Welcome to the custom site mysitedefinition </ H1 > < Webpartpages : Webpartzone ID = "Zoon1" Runat = "Server" Title = "Zoon1"> < Zonetemplate > </ Zonetemplate > </ Webpartpages : Webpartzone > </ ASP : Content >