如何编写一个加法器？

form action="./calculation.asp">

input type="text" size="1" name="op1 value=%Response.Write Request("op1")%>>

input type="submit" name="operation value="plus">

input type="text" size="1" name="op2 value=%Response.Write Request("op2")%>>

equals

%

   Dim result

   If Request("operation") = "plus" Then

      result = CLng(Request("op1")) + CLng(Request("op2"))

   Else

      result = "?"

   End If

   Response.Write result

%> 

/form>