GridView with a single ModalPopupExtender/Panel for row editing

<?xml version="1.0" encoding="utf-8"?>
<xs:schema xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xs="http://www.w3.org/2001/XMLSchema">
	<xs:element name="Data">
		<xs:complexType>
			<xs:sequence>
				<xs:element name="PersonTable">
					<xs:complexType>
						<xs:sequence>
							<xs:element maxOccurs="unbounded" name="Person">
								<xs:complexType>
									<xs:attribute name="PersonID" type="xs:int" use="required" />
									<xs:attribute name="FirstName" type="xs:string" use="required" />
									<xs:attribute name="LastName" type="xs:string" use="required" />
									<xs:attribute name="MiddleName" type="xs:string" use="optional" />
									<xs:attribute name="BirthDate" type="xs:string" use="required" />
									<xs:attribute name="Gender" type="xs:string" use="optional" />
									<xs:attribute name="Height" type="xs:unsignedByte" use="optional" />
									<xs:attribute name="Weight" type="xs:unsignedShort" use="optional" />
								</xs:complexType>
							</xs:element>
						</xs:sequence>
					</xs:complexType>
				</xs:element>
				<xs:element name="PhoneTable">
					<xs:complexType>
						<xs:sequence>
							<xs:element maxOccurs="unbounded" name="Phone">
								<xs:complexType>
									<xs:attribute name="PersonPhoneID" type="xs:int" use="required" />
									<xs:attribute name="PersonID" type="xs:int" use="required" />
									<xs:attribute name="PhoneTypeID" type="xs:unsignedByte" use="required" />
									<xs:attribute name="PhoneNumber" type="xs:string" use="required" />
									<xs:attribute name="Extension" type="xs:string" use="required" />
								</xs:complexType>
							</xs:element>
						</xs:sequence>
					</xs:complexType>
				</xs:element>
				<xs:element name="InternetAddressTable">
					<xs:complexType>
						<xs:sequence>
							<xs:element maxOccurs="unbounded" name="InternetAddress">
								<xs:complexType>
									<xs:attribute name="PersonInternetAddressID" type="xs:int" use="required" />
									<xs:attribute name="PersonID" type="xs:int" use="required" />
									<xs:attribute name="InternetAddress" type="xs:string" use="required" />
								</xs:complexType>
							</xs:element>
						</xs:sequence>
					</xs:complexType>
				</xs:element>
			</xs:sequence>
		</xs:complexType>
		<xs:key name="PhoneKey">
			<xs:selector xpath=".//Phone" />
			<xs:field xpath="@PersonPhoneID" />
		</xs:key>
		<xs:key name="PersonKey">
			<xs:selector xpath=".//Person" />
			<xs:field xpath="@PersonID" />
		</xs:key>
		<xs:key name="InternetAddressKey">
			<xs:selector xpath=".//InternetAddress" />
			<xs:field xpath="@PersonInternetAddressID" />
		</xs:key>
		<xs:keyref name="PersonPhone" refer="PersonKey">
			<xs:selector xpath=".//Phone" />
			<xs:field xpath="@PersonID" />
		</xs:keyref>
		<xs:keyref name="PersonInternetAddress" refer="PersonKey">
			<xs:selector xpath=".//InternetAddress" />
			<xs:field xpath="@PersonID" />
		</xs:keyref>
	</xs:element>
</xs:schema>