Urgent : Workflow with two steps

Hi All,

i am doin a workflow in which i am using a activity step first to display the PO/SO and then a user decision step for either approving or rejecting it.

bt once the activity step (work item in SAP inbox) is executed, the workflow is terminated.

the user decision step is not executed.

can anyone assist how can i make both step work synchronously?

Thanks in advance.