Internet problem, can't locate it

Made this game in order to learn internet programming, it's a simple twoplayer game where the goal is to place 5 marks in a straight line and prevent your opponent from doing so. The game works fine when I run two copies of it on my own machine and use the local ip for both of them (127.0.0.1). But when playing over the internet, the host can't send his first data package, however the host will recieve the ready message from the client, so some of it works. I'm using "port" 8765 and 8766, whatever that might be, and if that is wrong, then how can the first message go troug? Can anybody help me?

If you want to exec it pleace load the game from my storeroom (would like to call it a homepage)

Global plno=1
Global x
Global y
Global turn
Const boardsize=16
ip$=Input("Enter opponents IP:  ")
strmGame=OpenTCPStream(ip,8765)
If strmgame=0 Then
	svrGame=CreateTCPServer(8765)
	Print "Reciever didn't answer, wait for call"
Else
	WriteString strmGame,"Ready"
	CloseTCPStream strmgame
	Print "Reciever answered, establishing contact"
	plno=2
End If
If plno=1 Then
	Repeat
		strtream=AcceptTCPStream(svrGame)
		If strtream<>0 Then
			alpha$=ReadString$(strtream)
			If alpha="Ready" Then Exit
		End If
		Delay 10
	Forever
Else
	svrGame=CreateTCPServer(8766)
End If
Graphics boardsize*16,boardsize*16,32,2
ClsColor 255,255,0
Cls
Color 0,0,0
For a=0 To boardsize
	Rect a*16-1,0,2,boardsize*16
	Rect 0,a*16-1,boardsize*16,2
Next
Dim board(boardsize+1,boardsize+1)
Dim mark(1)
mark(0)=LoadImage("1.bmp")
mark(1)=LoadImage("2.bmp")
turn=1
Repeat
	If turn=plno Then
		Delay 200
		.nogood
		While Not MouseDown(1)
		Delay 5
		Wend
		x=MouseX()/16
		y=MouseY()/16
		If board(x+1,y+1)<>0 Then Goto nogood
		DrawImage mark(plno-1),x*16,y*16
		board(x+1,y+1)=plno
		.nogood2
		strmGame=OpenTCPStream(ip,8767-plno)
		If strmgame=0 Then Goto nogood2
		WriteByte strmGame,x
		WriteByte strmgame,y
		CloseTCPStream strmgame
	Else
		strtream=0
		While strtream=0
			strtream=AcceptTCPStream(svrGame)
			Delay 5
		Wend
		x=ReadByte(strtream)
		y=ReadByte(strtream)
		board(x+1,y+1)=turn
		DrawImage mark(2-plno),x*16,y*16
	End If
	Dim l(3)
	Dim active(7)
	For nostep=1 To 4
		check(0,1,0,nostep)
		check(1,1,1,nostep)
		check(1,0,2,nostep)
		check(1,-1,3,nostep)
	Next
	turn=3-turn
Forever
Function check(x1,y1,lineno,factor)
	If active(lineno)=0 Then
		If board(x+1+x1*factor,y+1+y1*factor)=turn Then l(lineno)=l(lineno)+1
		If board(x+1+x1*factor,y+1+y1*factor)<>turn Then active(lineno)=1
	End If
	If active(lineno+4)=0 Then
		If board(x+1-x1*factor,y+1-y1*factor)=turn Then l(lineno)=l(lineno)+1
		If board(x+1-x1*factor,y+1-y1*factor)<>turn Then active(lineno+4)=1
	End If
	If l(lineno)=>4 Then
		Rect 0,0,boardsize*16,16
		Color 0,255,255
		If turn=plno Then Print "You are victorious!"
		If turn<>plno Then Print "You have lost!"
		WaitKey()
		End
	End If
End Function

Hi eBusiness,
I can't try your code now, but I have some advice for you:

- you appear to close the tcpstream strmgame - if you close it, and then create a new one, the old connection is lost. Do not close it if you want stay connected.

- don't use goto - use structured language, that is, functions and the like.

- re-design your code completely. Use a 'status' variable, and a select case statement, to decide what to do at each status value.

- read my tcp internet chat example, it is in code archive, the link should be in my sig.

Hope this helps,
Sergio.

ReadAvail, didn't notice that command until I saw it in your code, thx. Still dunno what's wrong about my code, but I think I can solve the game now. Think Blitz need a general instruction on how to use the network commands.

So, the first game on the internet have been succesfully played, seems like those of my friends that I have tested the game with are not capable of obtaining the server function, and as both players are servers in the above code, it will result in an error, dunno why they can't.

Here is the new code, semars code helped me a lot.

Global plno=1
Global x
Global y
Global turn
Const boardsize=16
giveaway=0
Print "Enter an adress to call, or press enter in order"
ip$=Input("to wait for a call:  ")
If ip="" Then
	server=CreateTCPServer(8765)
	Print "Waiting for call"
	While conn=0
		conn=AcceptTCPStream(server)
		Delay 100
	Wend
	SeedRnd(MilliSecs())
	giveaway=Rand(0,1)
Else
	conn=OpenTCPStream(ip,8765)
	plno=2
	If conn=0 Then End
End If

Graphics boardsize*16,boardsize*16+16,32,2
ClsColor 255,255,0
Cls
Color 0,0,0
For a=0 To boardsize
	Rect a*16-1,0,2,boardsize*16
	Rect 0,a*16-1,boardsize*16,2
Next
Dim board(boardsize+1,boardsize+1)
Dim mark(1)
mark(0)=LoadImage("1.bmp")
mark(1)=LoadImage("2.bmp")
turn=1+giveaway
If giveaway=1 Then WriteShort conn,65535
Repeat
	Color 0,0,0
	Rect 0,256,boardsize*16,16
	Color 256,255,255
	If turn=plno Then
		Text 0,256,"Your turn"
		Delay 200
		.nogood
		While Not MouseDown(1)
		Delay 5
		Wend
		x=MouseX()/16
		y=MouseY()/16
		If board(x+1,y+1)<>0 Then Goto nogood
		DrawImage mark(plno-1),x*16,y*16
		board(x+1,y+1)=plno
		WriteByte conn,x
		WriteByte conn,y
	Else
		Text 0,256,"Your opponent is drawing"
		While ReadAvail(conn)<2
			Delay 5
		Wend
		x=ReadByte(conn)
		y=ReadByte(conn)
		If x<>255 Then
			board(x+1,y+1)=turn
			DrawImage mark(2-plno),x*16,y*16
		End If
	End If
	Dim l(3)
	Dim active(7)
	For nostep=1 To 4
		check(0,1,0,nostep)
		check(1,1,1,nostep)
		check(1,0,2,nostep)
		check(1,-1,3,nostep)
	Next
	turn=3-turn
Forever
Function check(x1,y1,lineno,factor)
	If active(lineno)=0 Then
		If board(x+1+x1*factor,y+1+y1*factor)=turn Then l(lineno)=l(lineno)+1
		If board(x+1+x1*factor,y+1+y1*factor)<>turn Then active(lineno)=1
	End If
	If active(lineno+4)=0 Then
		If board(x+1-x1*factor,y+1-y1*factor)=turn Then l(lineno)=l(lineno)+1
		If board(x+1-x1*factor,y+1-y1*factor)<>turn Then active(lineno+4)=1
	End If
	If l(lineno)=>4 Then
		Color 0,0,0
		Rect 0,256,boardsize*16,16
		Color 256,255,255
		If turn=plno Then Text 0,256,"You are victorious!"
		If turn<>plno Then Text 0,256,"You have lost!"
		WaitKey()
		End
	End If
End Function

Think it need some minor gameplay changes thou.
Edit: Minor gamplay changes have been added.