一个让人极度无语的错误

[023it]

if isnull(Rs("strFixing")) then
strFixing = ""
Response.write "null<br>"
else
strFixing = Rs("strFixing")
Response.write "not null<br>"
end if
if strFixing = "" Then
Response.write "空"
elseif isnull(strFixing) then
response.write "Null"
end if

两个if语句后，执行后的显示记过为not null<br>Null
不知道有没有朋友看出无语的地方了，谁来救救我