For-Next INSIDE While - Wend

I have spent the last 2 days trying to get a For-Next to work Inside a While-Wend. But I keep getting a BLOCK MISMATCH error. The manual for PBP V2.50b offered little to no help and I can't find it here on the Forum. So where do I look?

Thanks ONE and All
Terry K9HA

Please post some code

Here is some code from a working program that has a FOR ... NEXT within a WHILE .... WEND. I did not throw up any problems when I wrote it or since. It runs on an 18F4620 and is compiled in PBPL.

Code:

---

SendPacket:
      txchksum = 0
      msgloops = 0
      txmsglen = txchar[3]
      while ack = 0            'destination has not yet got a clean copy
        msgloops = msgloops + 1
        if msgloops > 63 then msglooperror    ' send packet maximum of 64 times
        for commsctr = 0 to precnt
            serout2 msg, 32, [prechar]    'send preamble
        next commsctr
        serout2 msg, 32, ["$"]    'send Start Of Message
        for commsctr = 0 to 255  'send rest of message - won't get to 255
            if commsctr = txmsglen then sendeom
            serout2 msg, 32, [txchar[commsctr]]
            txchksum = txchksum + txchar[commsctr]
            'active message length is 0~(TxMsgLen - 1)
            'EOM is at position TxChar[TxMsgLen]
        next commsctr
        SendEOM:    'plus the SendChkSum:
        serout2 msg, 32, ["*",txchksum]
        txchar[txmsglen] = "*"
        txchar[txmsglen + 1] = txchksum

      wend

---

HTH
BrianT

Thank you BRIAN!!,,
Brian your code example was a real help. In my code I had a conditional If Then, some how
during the marathon coding session I had dropped a EXTRA endif in. The compilier knew that there was a problem, told me there was a problem, but did not tell me WHAT the problem. So, I think I will "borrow" a programming trick from Skimask, DT, etal. SWITCH TO COKE! The DRINK that is!

Again, I want thank ONE AND ALL, for their help.