problem in building flash Algorthim for new flash device using keil uvision -3

As per the direction in uvision help regarding Adding New Flash Algorithm .We used already available LPC3250_Nand_sp algorithm for creating flash algorithm (our requirement: Is to build Flash Algorithm for External 8 bit Nand Flash Large Page for LPC3250).

But before making any changes to above program we tried to build LPC3250_Nand_sp.FLX file .Since this file was already available so we removed it from the FLASH Folder. Without making change to original program we tried to build, but following linker error occurred

1) l6265e 2) l6248e These we sorted out by enabling the option "use memory layout from target dialog" in Linker option.

On compilation above error were removed and new error came up in .sct file l6236e.
.\Output\LPC3000_NAND_SP.sct(7): error: L6236E: No section matches selector - no section to be FIRST/LAST.

Now if we add following code to our code

AREA RESET, CODE, READONLY END

Error is removed and LPC3250_Nand_sp.FLX file is generated.
My question: 1) Why we have to make so many changes to generate .FLX file

2) Is it a Tool Problem

3) The procedure we have followed is correct or not

4) If not what is the correct Procedure to generate .FLX file for new flash