问题解决了，then 后边的语句不能跟之前的语句在一行上

<%
Response.write(Time())
Response.Write(Hour(Time()))
mydate=Hour(Time())
Response.Write(mydate)
  

if ((mydate>=12) and (mydate <=18)) Then
Response.write("下午好！")
Else If ((mydate>18)and(mydate<=24))
Then Response.write("晚上好！")
Else If ((mydate>0)and(mydate<=6))
Then Response.write("夜间好！")
Else ((mydate>6)and(mydate<12))
Then Response.write("早上好！")
End If
%>
一键之差，差了这么多