检查空字段和显示红色警告消息（Javascript）

本文介绍了检查空字段和显示红色警告消息（Javascript）的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

我有一个文本字段和一个如下所示的列表：

I have a textfield and a list which looks like this :

<form name="myform" method="post" action="register.php"> Username : <input name="username" type="text"> Country : <select name="country"> <option value="" selected></option> <option value="Afghanistan">Afghanistan</option> </select> <input name="submit" type="button" value="REGISTER"> </form>

首先，我想检查是否有空字段。然后，如果有空字段，则在文本字段旁边显示红色警告消息，如空用户名或空国家。因此，当我按下REGISTER按钮时，如果有空字段，它将显示警告。否则，它将进入register.php 提前致谢！

First, I want to check if there is empty field. Then, if there is empty field , display a red warning message like "Empty username" or "Empty Country" beside the textfield. So, when i press REGISTER button, it will display warning if there is any empty field. Otherwise, It will proceed to register.php Thanks in advance!

推荐答案

看看这些链接在Javascript表单验证 - JavaScript表单验证 [ ^ ] JavaScript - 表单验证 [ ^ ] Javascript验证 [ ^ ] [ ^ ] Have a look at these links on Javascript form validation - JavaScript Form Validation[^] JavaScript - Form Validation[^] Javascript Validation [^] Client Side Validation using JavaScript[^]