把下面这两段加密，解密的代码用VB的语法写出来 ( 积分: 100 )

function EncrypStr(Src, Key: String): String;
//对字符串加密(Src:源 Key:密匙)
var KeyLen :Integer;
KeyPos :Integer;
offset :Integer;
dest :string;
SrcPos :Integer;
SrcAsc :Integer;
Range :Integer;
begin
KeyLen:=Length(Key);
if KeyLen = 0 then
key:='delphi';
KeyPos:=0;
Range:=256;
Randomize;
offset:=Random(Range);
dest:=format('%1.2x',[offset]);
for SrcPos := 1 to Length(Src)do
begin
SrcAsc:=(Ord(Src[SrcPos]) + offset) MOD 255;
if KeyPos < KeyLen
then
KeyPos:= KeyPos + 1
else
KeyPos:=1;
SrcAsc:= SrcAsc xor Ord(Key[KeyPos]);
dest:=dest + format('%1.2x',[SrcAsc]);
offset:=SrcAsc;
end;
Result:=Dest;
end;

function UncrypStr(Src, Key: String): string;
//对字符串解密(Src:源 Key:密匙)
var KeyLen :Integer;
KeyPos :Integer;
offset :Integer;
dest :string;
SrcPos :Integer;
SrcAsc :Integer;
TmpSrcAsc :Integer;
begin
KeyLen:=Length(Key);
if KeyLen = 0 then
key:='delphi';
KeyPos:=0;
offset:=StrToInt('$'+ copy(src,1,2));
SrcPos:=3;
repeat
SrcAsc:=StrToInt('$'+ copy(src,SrcPos,2));
if KeyPos < KeyLen
then
KeyPos := KeyPos + 1
else
KeyPos := 1;
TmpSrcAsc := SrcAsc xor Ord(Key[KeyPos]);
if TmpSrcAsc <= offset
then
TmpSrcAsc := 255 + TmpSrcAsc - offset
else
TmpSrcAsc := TmpSrcAsc - offset;
dest:=dest + chr(TmpSrcAsc);
offset:=srcAsc;
SrcPos:=SrcPos + 2;
until SrcPos >= Length(Src);
Result:=Dest;
end;