TTcp communication

     I want  to use TTcp in delphi 3 to communicate two hosts.  and the
two hosts can be server and client at the same time.   I use two Tcp,
one for server and listen at port 7 , the other is  used as client. when

there is request, Using the client Tcp accept. At runtime, two hosts
are  keeping  listen first. when one host want send data, it use client
Tcp to connect the other host. but I meet two  problem can't solve:
1.At first connect,  the server can send data to client but client can't

send data back to server. then I  use close method at server host,  then

reconnect at client host ,
thing is ok, how to solve this problem?
2.At client host, though I use close method to close server and client
Tcp,  there is error message 'address in use' when I want to reconnect
the server host.

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