function wait

Hi, I´m a begginer!

And a i´m trying to read a database from a .dat arquive, and i had trouble with the function wait... i took the program from the internet

It appears on the srcreen :

Error (10533): VHDL Wait Statement error at read_site.vhd(33): Wait Statement must contain condition clause with UNTIL keyword

my program is this one

-- versao VHDL-1993capa_1ra

--

ENTITY read_site IS

GENERIC(n : INTEGER := 2);

PORT(dado_lido : OUT STRING(1 TO n);

tamanho : OUT NATURAL); --

END read_site;

ARCHITECTURE teste OF read_site IS

TYPE vetor_2d IS ARRAY(0 TO 7) OF STRING(1 TO 3);

CONSTANT dado_escrito : vetor_2d := ("abc","def","ghi","jkl","mno","pqr","stu","vxz");

TYPE arquivo_u IS FILE OF STRING;

FILE arq_rd : arquivo_u;

TYPE arquivo_c IS FILE OF STRING(1 TO 3);

FILE arq_wr : arquivo_c;

BEGIN

escreve_le: PROCESS

VARIABLE dado_lido_v : STRING(1 TO n);

VARIABLE tamanho_v : NATURAL;

BEGIN

FILE_OPEN(arq_wr, "\vhd\dado_j.dat",Write_Mode);

FOR i IN 0 TO 7 LOOP

WRITE(arq_wr, dado_escrito(i));

END LOOP;

FILE_CLOSE(arq_wr);

FILE_OPEN(arq_rd, "\vhd\dado_j.dat",Read_Mode);

WHILE NOT ENDFILE(arq_rd) LOOP

READ(arq_rd, dado_lido_v, tamanho_v);

dado_lido <= dado_lido_v;

tamanho <= tamanho_v;

WAIT FOR 10 ns;

END LOOP;

WAIT;

END PROCESS escreve_le;

END teste;

There is something to wrong in them?

thanks