diff --git a/code/post.f90 b/code/post.f90
index bbbf9eb..9ee0d92 100644
--- a/code/post.f90
+++ b/code/post.f90
@@ -103,7 +103,6 @@
      SUBROUTINE main_lb
       INTEGER :: fread,i
       INTEGER, PARAMETER :: eofread = -1
-      LOGICAL :: received
 
       CALL READ_INTRO
 
@@ -134,14 +133,8 @@
 
                   countnum=countnum+1
 
-                  CALL MPI_Irecv(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_request, mpi_err)
-                  do
-                      call MPI_Test(mpi_request, received, mpi_status, mpi_err)
-                      if (received) exit
-                      call SLEEP (1)
-                  end do
-
-                  CALL MPI_SEND(fread, 1, MPI_INTEGER8, id_to, tag, MPI_COMM_TASK, mpi_err)
+                  CALL MPI_RECV(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_status, mpi_err)
+                  CALL MPI_SEND(fread, 1, MPI_INTEGER8, id_to,         tag, MPI_COMM_TASK, mpi_err)
 
               ENDIF
 
@@ -149,14 +142,8 @@
 
           end_of_dispatch1: DO i=1,numprocs-1
 
-              CALL MPI_Irecv (id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_request, mpi_err)
-              do
-                call MPI_Test(mpi_request, received, mpi_status, mpi_err)
-                if (received) exit
-                call SLEEP (1)
-              end do
-
-              CALL MPI_SEND(eofread, 1, MPI_INTEGER8, id_to, tag, MPI_COMM_TASK, mpi_err)
+              CALL MPI_RECV(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_status, mpi_err)
+              CALL MPI_SEND(eofread, 1, MPI_INTEGER8, id_to,       tag, MPI_COMM_TASK, mpi_err)
 
           ENDDO end_of_dispatch1
 
@@ -204,14 +191,8 @@
 
               ELSE
 
-                  CALL MPI_Irecv(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_request, mpi_err)
-                  do
-                      call MPI_Test(mpi_request, received, mpi_status, mpi_err)
-                      if (received) exit
-                      call SLEEP (1)
-                  end do
-
-                  CALL MPI_SEND(fread, 1, MPI_INTEGER8, id_to,          tag, MPI_COMM_TASK, mpi_err)
+                  CALL MPI_RECV(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_status, mpi_err)
+                  CALL MPI_SEND(fread, 1, MPI_INTEGER8, id_to,         tag, MPI_COMM_TASK, mpi_err)
 
               ENDIF
 
@@ -219,14 +200,8 @@
 
           end_of_dispatch2: DO i=1,numprocs-1
 
-              CALL MPI_Irecv (id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_request, mpi_err)
-              do
-                call MPI_Test(mpi_request, received, mpi_status, mpi_err)
-                if (received) exit
-                call SLEEP (1)
-              end do
-
-              CALL MPI_SEND(eofread, 1, MPI_INTEGER8, id_to,          tag, MPI_COMM_TASK, mpi_err)
+              CALL MPI_RECV(id_to, 1, MPI_INTEGER, MPI_ANY_SOURCE, tag, MPI_COMM_TASK, mpi_status, mpi_err)
+              CALL MPI_SEND(eofread, 1, MPI_INTEGER8, id_to,       tag, MPI_COMM_TASK, mpi_err)
 
           ENDDO end_of_dispatch2