[PIC] dsPIC30F5013 ERASE PROGRAM MEMORY

Hi,
I need to wipe the program memory entirely (all bits at 0) of my dsPIC30F5013,
why doesn't this code work?

oldAddress=0x100;
while(oldAddress<0x00AFFE){
addressToWrite=oldAddress;
if(oldAddress+16<=0x00AFFE)
break;
else
WriteWord(addressToWrite,0);
oldAddress+=16;
}


function WriteWord is defined in in eeprom_rw.s written by btbass (library included in the code):
;------ Write a word to eeprom
_WriteWord:
push w4
mov #ADDRESS_HI,w4
mov w4,TBLPAG
mov w4,NVMADRU
mov #ADDRESS_LO,w4
sl w0,#1,w0
add w0,w4,w0
mov w0,NVMADR
rcall EraseWord
mov #WRITE_WORD,w4
mov w4,NVMCON
TBLWTL w1,[w0]
rcall KeySequence
pop w4
return