xml message creation with default name space

Hi,

I need to create xml message. I was trying to manually create xml message to make sure it is in valid format. I am getting error with below xml format

<myRequest xmlns:xsi="http://www.hi.com/HH8/09876543" xmlns="http://www.hi.com/HH8/09876543" >  (no prefix. I just assigned value to xmlns). We are sending this message to third party vendor.

  <element1>

     ........

   </element1>

</myRequest>

element1 is showing curly underline which means it is an error.

If I do <element1 xmlns:"">, then it is fine.

I do not want to prefix name space any sub elements. I was it to be default namespace with url assigned.

How can I do that.

Thank You