Hi all, please, help.

I need to use REST for creating new portal user
I use apigee.com.
I create class and GET works well, but I have problems with POST.

@RestResource(urlMapping='/WSPortalUser/*')
global with sharing class WSPortalUser{

    @HttpGet
    global static User doGet(){
        RestRequest req = RestContext.request;
        RestResponse res = RestContext.response;
        String userId = req.requestURI.substring(req.requestURI.lastIndexOf('/')+1);
        User result = [SELECT Id, Name FROM User WHERE Id = :userId];
        return result;
    }
  
    @HttpPost
    global static String doPost(String name){
    	return name;
    }
}

 GET:

https://na14.salesforce.com/services/apexrest/WSPortalUser/005i0000000M2lB

HTTP/1.1 200 OK
Date:
Thu, 13 Jun 2013 02:44:33 GMT
Content-Length:
144
Content-Type:
application/json;charset=UTF-8

{
  "attributes":  {
    "type": "User",
    "url": "/services/data/v24.0/sobjects/User/005i0000000M2lBAAS"
  },
  "Name": "Admin",
  "Id": "005i0000000M2lBAAS"
}

 POST:

https://na14.salesforce.com/services/apexrest/WSPortalUser?name=TestName

HTTP/1.1 400 Bad Request
Date:
Thu, 13 Jun 2013 02:53:18 GMT
Content-Length:
118
Content-Type:
application/json;charset=UTF-8

[
   {
    "message": "The HTTP entity body is required, but this request has no entity body.",
    "errorCode": "JSON_PARSER_ERROR"
  }
]

 What do I do wrong? Please, any ideas.