Code:

function BinToInt(const Value: string): Integer;

{©Drkb v.3(2007): www.drkb.ru}

var

i, strLen: Integer;

begin

Result := 0;

strLen := Length(Value);

for i := 1 to strLen do

   if Value[i] = '1' then

     Result := Result or (1 shl (strLen - i))

   else

     Result := Result and not (1 shl (strLen - i));

end;