class structure for repeating sequence of repeating elements?

[Neil Waldie]

I am trying to code a class for use with the XMLSerializer that can produce
XML valid for the following schema (fragment):

<xs:element name="Group">
<xs:complexType>
<xs:sequence minOccurs="1" maxOccurs="unbounded">
<xs:element name="SubElement1" />
<xs:element minOccurs="0" maxOccurs="1" name="SubElement2" />
<xs:element minOccurs="0" maxOccurs="1" name="SubElement3" />
</xs:sequence>
</xs:complexType>
</xs:element>

Can anyone help with this (VB or C#)? If I try the following simple example,
I get an additional element (a) which is not what I need! (I know I declare
the array as an element, and this may be the problem, but I need to do
something there that specifies the type of the collected class, or I get an
exception when serializing)

class SubElements
public SubElement1 as string = "SubElement1Text"
public SubElement2 as string = "SubElement1Text"
public SubElement3 as string = "SubElement1Text"
end class

class Group
<XMLElement(Type:=GetType(SubElements)> _
public a as new ArrayList

sub new()
a.Add(new SubElements)
a.Add(new SubElements)
end sub
end class

Many thanks,

Neil