Generate HTML string from an XML

Question

    //My C# code
           XmlTextReader reader = new XmlTextReader(@"D:\test.xml");
                    while (reader.Read())
                    {                             
                        switch (reader.NodeType)
                        {
                            case XmlNodeType.Element: 
                                htmlstring+=reader.Name;                                    
                                break;
                            case XmlNodeType.Text: 
                                htmlstring += reader.Value;                                    
                                break;
                        }
                    }

//My xml document

    <Groups>
	<Group1>
		<Item1>
			<GUID>124342345</GUID>
			<Title>Name</Title>
			<Type>Button</Type>			
		</Item1>
	</Group1>
</Groups>