XML security namespace from WCF code

Hi,

I am using 3rd party service URL from my WCF code and defining everything from code and database, not from web.config. Defining HTTPBinding and binding elements also from code.

BasicHttpBinding basicHttpBinding = new BasicHttpBinding();
basicHttpBinding.Security.Mode = BasicHttpSecurityMode.TransportWithMessageCredential;
basicHttpBinding.Security.Transport.ClientCredentialType = HttpClientCredentialType.None;
basicHttpBinding.Security.Transport.ProxyCredentialType = HttpProxyCredentialType.None;
basicHttpBinding.Security.Message.ClientCredentialType = BasicHttpMessageCredentialType.UserName;

BindingElementCollection _bindingElements = _myClient.Endpoint.Binding.CreateBindingElements();
_bindingElements.Find().IncludeTimestamp = false;
_myClient.Endpoint.Binding = new CustomBinding(_bindingElements);

While executing when i trace the XML it is as below. Highlighted bold part in security name space is taking by default as oasis which is not working for me. If needs to be changed to http://schemas.xmlsoap.org/ws/2003/06/secext" to get response.

How to change it? please help me

????

xmlns="http://schemas.microsoft.com/vstudio/diagnostics/servicemodelsink">uIDPo5TOJ2Q58qNIi1IeasoccCoAAAAAmQ7W7B5fYEmXWhpPpmkTt5pjD8GGqodIgjeeX+Rgg7IACQAA
"http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd">

Username
Password

Please help me.

Thank you...