reqEnv.declareNamespace("http://soapinterop.org/xsd","s");
reqEnv.declareNamespace("http://soapinterop.org/","m");
SOAPHeader header = omfactory.createSOAPHeader(reqEnv);
OMNamespace hns= reqEnv.declareNamespace("http://soapinterop.org/echoheader/","hns"); //xmlns:m0="http://soapinterop.org/echoheader/
SOAPHeaderBlock block1 = header.addHeaderBlock("echoMeStringRequest",hns);
block1.addAttribute("xsi:type","xsd:string",null);
block1.addChild(omfactory.createText("string"));
// header.addChild(headerChild);
header.addChild(block1);