workflow foundation 4 - Using OutArgument in Definition of another Activity -

i'm creating workflow can call custom activity called post webrequest , return response xmldoc. tried return dynamic didn't work. want take specific value in xml doc , add post dada of next post call chain calls together. can't figure out how response data first post post data of second post. appreciated.

        variable<xmldocument> output1 = new variable<xmldocument>();          activitybuilder ab1 = new activitybuilder();         ab1.name = "customworkflow";         ab1.implementation = new sequence                              {                                  activities =                                  {                                      new post()                                      {                                          postdata =                                              "<xml></xml>",                                          endpoint =                                              "www.test.com",                                          contenttype = "text/xml;charset=\"utf-8\"",                                          accept = "text/xml",                                          headers = "soapaction,test",                                          response = new outargument<xmldocument>(output1)                                      },                                      new post()                                      {                                          postdata =                                              "<xml>"+ output1.getsinglenode("stuff here") "</xml>",                                          endpoint =                                              "www.test.com",                                          contenttype = "text/xml;charset=\"utf-8\"",                                          accept = "text/xml",                                          headers = "soapaction,test"                                      }                                  },                                  variables =                                  {                                      output1                                  }                              }; 

think asking: how transfer value 1 activity another. if so, there couple of ways this.

1) have variable @ workflow level takes output first activity , pass variable input parameter next activity.

2) have variable data structure , pass structure activities in sequence. in each activity can add/edit/delete data in structure , because workflow variable reference variable data available next activity sequence once pass in data object. instead of variable can use argument if want pass initial data workflow. on arguments behaves variables