Выдает ошибку,в чем дело

program dekanat;
uses dos,crt;
const CSize=1000;
type
Tgruppi=record
mSpicialnost:string;
mNomerGruppi:integer;
mFamilia:string;
mIma:String;
mOtchestvo:string;
mRodilsa:real;
end;
PGruppi=^TGruppi;
type
Tbase=array[1..CSize] of PGruppi;
var
DataBase:TBase;
count:integer;
function ReadData(var F:text):integer;
var
P:Pgruppi;
S:string;
t:string;
N:integer;
A:string;
M:string;
O:string;
R:real;
J:integer;
begin
assign(f,'f:\praktika\dekanat.txt');
reset(f);
j:=0;
while not eof(f) and (j<CSize) do begin
inc(j);
 
readln(F,T);
readln(F,N);
readln(F,A);
readln(F,M);
readln(F,O);
readln(F,R);
new(P);
 
P^.mSpecialnost:=T;
P^.mNomerGruppi:=N;
P^.mFamilia:=A;
P^.mIma:=M;
P^.mOtchestvo:=O;
P^.mRodilsa:=R;
DataBase[j]:=P;
end;
close(f);
readdata:=j;
dispose(p);
end;
 
procedure ExpoDataBase;
var j:integer;
begin
j:=1;
while (j<=CSize) and assigned(DataBase[j]) do begin
writeln(DataBase[j]^.mSpecialnost:10,'':2,DataBase[j]^.mNomerGruppi:6:2,'':6,
DataBase[j]^.mFamilia:9,'':2,DataBase[j]^.mIma:7,'':1,DataBase[j]^.mOtchestvo:9,'':12,
DataBase[j]^.mRodilsa:5:2);
inc(j);
end;
end;
 
var f:text; j:integer;
begin
clrscr;
for j:=1 to CSize do DataBase[j]:=nil;
count:=readdata(f);
writeln('Vsego zapisei:',Count);
writeln('________________________________________________________________________________');
Writeln(' Specialnost|','':3,' NomerGruppi   |','':3,' Familia  |','':3,' Ima |','':3,' Otchestvo |','':3,' Rodilsa':2);;
writeln('________________________________________________________________________________');
ExpoDataBase;
 
readln;
end.