def doctype(xml, style_src=nil)
xml << '<html id="root" xmlns="http://www.w3.org/1999/xhtml"
xmlns:xf="http://www.w3.org/2002/xforms"
xmlns:m="http://www.mobio.com/ext"
xmlns:ext="http://www.mobio.com/ext"
xmlns:ev="http://www.w3.org/2001/xml-events">'
@model_buffer = '<head>'
@model_buffer << '<style xmlns="http://www.mobio.com/ext" src="' << style_src << '"/>' if style_src
@model_buffer << "\n<model>"
yield xml
@model_buffer << "</model></head>\n"
xml << @model_buffer << @view_buffer
xml << "</html>"
end