小编Ram*_*ill的帖子

我有一个问题,验证字段是空的还是满的.以下代码将有所帮助.

以下不是我的整个表格,只是你需要知道的部分.HTML:

<form action="" method="post" id="all_message">
    <ul>
        <li>
            <label for="subject">Subject</label><br />
            <select id="No_dropdown" name="Dropown_select">
                <option value="Request for quote">Request for quote</option>
                <option value="Service inquiries">Service inquiries</option>
                <option value="Other">Other</option>
            </select>
        </li>
        <li>
            <input type="submit" value="Send" name="submit" />
        </li>
    </ul>
</form>

我使用此脚本对上面的选择选项进行无选择.使用Javascript

<script language="javascript" type="text/javascript">
document.getElementById("No_dropdown").selectedIndex = -1;
</script>

这不是整个PHP,只是我遇到麻烦的部分.PHP:

$subject =      $_POST['Dropown_select'];

if (empty($name) === true || empty($email) === true || empty($phone) === true || 
    !($subject === "Other" || "Service inquiries" || "Request for quote") ||   
    empty($message) === true ) …

该程序应该从用户获得两个输入并显示答案.这些是我得到的错误:

(15):错误C2065:'x':未声明的标识符

(15):错误C2065:'y':未声明的标识符

(16):错误C2448:'writeanswer':函数式初始值设定项似乎是一个函数定义

(30):错误C3861:'writeanswer':找不到标识符

这是我的代码:

#include "stdafx.h"
#include <iostream>
using namespace std;

int Readnumber()
{
    int num;
    cin >> num;
    return num;
}

    void writeanswer(x, y) //THIS IS LINE 15
{ //THIS IS LINE 16
    int a;
    a = x + y;
    cout << "This is the answer: " << a;
}


int main()
{
    cout << "Please enter a number: ";
    int x = Readnumber();

    cout << "Please enter another number: ";
    int y = Readnumber();

    writeanswer(x, y); …