can't pass auth_token in webservice calls

Hello. Pls somebody explain to me how to pass auth_token in webservice calls. I am writing a small app using jquery mobile. I can succesfully get the token ($.ajax({type:'POST',url:http://mysite/service/api/rest/json/',data:'method=auth.gettoken'&username=user&password=password',dataType:'json'.....}

 

This returns a token e.g:df123dfgg455666...

 

I try to pass this as a parameter when making calls like blog.save_post but it gives me error. The readme says i have to pass auth_token in every web service call. Don't know how. Pls any help would be appreciated. I am using webservice plugin for this