Hi Dorin,

Thanks a lot to you and everyone for the ideas and code samples. For now I coded the simplest solution (just take the max number between source and BldMstr file and then increment the maximum). Since it's a single user application, this approach should work.

I would keep all suggestions for the future use.

Thanks again.

>Here is the code I use to generate some kind of numeric GUID.
>Double type column is nedeed as primary key
>
>

>FUNCTION MyGuid
>IF VARTYPE(nDriveSerialNumber) = 'U'
>	PUBLIC nDriveSerialNumber
>	IF DRIVETYPE(SYS(5)) <> 3
>		nDriveSerialNumber = DriveInfo('C:','SerialNumber')
>	ELSE
>		nDriveSerialNumber = DriveInfo(SYS(5),'SerialNumber')
>	ENDIF
>	
>ENDIF
>return Bin2Num( RIGHT(SYS(2015),9) )+ VAL(SYS(2007, SYS(0)))+ nDriveSerialNumber
>
>
>
>
>FUNCTION Bin2Num
>LPARAMETERS cString
>LOCAL lnRetNumber, lcChars, i , lncCharsLength, lcCurrentCh, lnPosition
>lcChars = "ABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789"
>lncCharsLength=LEN(lcChars)
>lnRetNumber = 0
>FOR i=1 TO LEN(cString)
>	lcCurrentCh=SUBSTR(cString,LEN(cString)- i + 1 , 1 )
>	lnPosition = AT( lcCurrentCh , lcChars )-1
>	lnRetNumber = lnRetNumber + lnPosition * (lncCharsLength**( i - 1 ))
>NEXT
>RETURN lnRetNumber
>
>
>
>FUNCTION DriveInfo
>LPARAMETERS tcDrive, tcRequiredInfo
>*
>* parameters :	tcDrive		drive ( "C:","D:", etc. , any type)
>*		tcRequiredInfo	AvailableSpace, DriveLetter, DriveType, FileSystem, FreeSpace
>*				IsReady, Path, RootFolder, SerialNumber, ShareName, TotalSize
>*				VolumeName								
>*		
>LOCAL oFs as "Scripting.FilesystemObject" , oDrv , lReturnValue , cInfo
>
>oFs = CREATEOBJECT("Scripting.FilesystemObject")
>oDrv = oFs.GetDrive(tcDrive)
>cInfo = "oDrv."+tcRequiredInfo
>lReturnValue = EVALUATE(cInfo)
>RELEASE oDrv,oFs
>
>RETURN lReturnValue
>

>
>
>>Hi everybody,
>>
>>Here is my situation:
>>
>>I've created Electronic Data Entry piece of Data Entry application. We receive files from registries in some text formats. I created a conversion program for each registry, that creates "source" file. Then another program processes this Source file and creates a work file, called BldMstr. This file has ID field called RecNum.
>>
>>There are some records in the source file, which should not go to the BldMstr file (nominal sales, for example). However, these records should go to "DoNotProcess" file.
>>
>>I number records in Source file sequentually.
>>
>>So, here is a scenario:
>>

>>BldMstr
>>   RecNum - 1
>>   RecNum - 2
>>   RecNum - 5
>>DoNotProcess
>>   RecNum - 3
>>   RecNum - 4
>>
>>
>>Source File
>>   RecNum - 1
>>   ...
>>   RecNum - 5

>>*************************************************************
>>In the Electronic Data Entry I allow some manipulations with BldMstr file, which basically allow to add new records. My problem is, I don't know, how to ensure, that each time, I add a record to this BldMstr file, I add a new unique ID.
>>
>>The DE application is stand-alone (not multiuser), so I was not using additional table (NextID table) idea...
>>
>>============================================================
>>Can you advise something in my situation, please?