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>