after reading soap specification at w3c i have a few questions

1) you can't use soap-envelope namespace with application specific
<element>?

since soap schema have not define namespace (env) can use with <MyElement>

inside soap schema -->

targetNamespace=http://www.w3.org/2003/05/soap-envelope

indicates that the elements defined by this schema are <Header>

for example: <env:MyElement> --> we cannot use the envlope namespace with
<MyElement>?

note: <MyElement> is an element generate from my own application

2) in soap schema we have

<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema"
xmlns:tns="http://www.w3.org/2003/05/soap-envelope"
targetNamespace="http://www.w3.org/2003/05/soap-envelope"
elementFormDefault="qualified">

in soap request xml we can delcare using that namespace by

<env:Envelope xmlns:env="http://www.w3.org/2003/05/soap-envelope">

so all element with env namespace will follow rules in soap schema at
http://www.w3.org/2003/05/soap-envelope/
is that correct?

at the same time all element in My namespace will follow rules in my new
schema that i define?

3) the above is why we need namespace?

for example -

a) soap-envelope namespace is a set of elements includes <Envelope> <Header>

b) WSDL namespace is for a set of elements <definitions> <types> <message>
<portType> <binding> .. etc etc

c) My own defined namespace is for a set of elements <MyElement> .. etc etc
that i defined.

so namespace can distinguish a set of elements in XML that's defined by
different people?

Thanks