JS表单验证不能用于简单的html表单 - JS Form Validation not working for simple html form

JS Form Validation not working for simple html form

我有一个简单的HTML表单，只有一个字段。格式如下-

<table> 
    <form action="insert.php" method="post" name="discover" onSubmit="return discover()">
    <tr><td></td><td><input type="text"  name="name"></td></tr>                                                             
    <tr><td></td><td><br><br><p class="submit"><input type="submit" id="submit" name="commit" value="Register"></p><br><br><br></td></tr>
    </form>
</table>

验证js文件是-

function discover() {
   var stu_name=document.forms["discover"]["name"].value;
   if (stu_name==null || stu_name=="" || stu_name.length<7) {
      alert("Please provide Your full name");
      return false;
   }  
}

我已经包含验证js文件正确。但这种验证不起作用。

try this

<script type="text/javascript">
function check()
{
var stu_name=document.forms["discover"]["stu_name"].value;
if (stu_name==null || stu_name=="" || stu_name.length<7)
  {
  alert("Please provide Your full name");
  return false;
  }
}
</script>
<form action="" method="post" name="discover" id="discover" onsubmit="return check();">
<input type="text" name="stu_name" id="stu_name" value="" />
<input type="submit" id="sub" />
</form>

在你的js文件中，

测试:

function discover()
{
var stu_name=document.forms["discover"]["name"].value;

if (stu_name==null || stu_name=="" || stu_name.length<7)
{
      alert("Please provide Your full name");
      return false;
   }
}

这个作品

function discover()
{
var stu_name=document.getElementsByName("name");

if (stu_name==null || stu_name=="" || stu_name.length<7)
{
      alert("Please provide Your full name");
      return false;
   }
}

您正在混合表单名称和函数名称，并且输入需要缺少的id。而且你忘了关闭函数。试试这个

<script type="text/javascript">
function _discover()
{
var stu_name=document.forms["discover"]["stu_name"].value;

if (stu_name==null || stu_name=="" || stu_name.length<7)
  {
  alert("Please provide Your full name");
  return false;
  }
}

</script>
<table> 
    <form action="" method="post" name="discover" onSubmit="return _discover();">
    <tr><td></td><td><input type="text"  name="name" id="stu_name"> </td></tr>                                                             
    <tr><td></td><td><br><br><p class="submit"><input type="submit" id="submit" name="commit" value="Register"></p><br><br><br></td></tr>
    </form>
</table>

您的代码中除了函数名与表单同名之外没有任何问题

查看这个链接，这里是工作代码

jsbin

function disc() {
   var stu_name=document.forms["discover"]["name"].value;
   if (stu_name==null || stu_name=="" || stu_name.length<7) {
      alert("Please provide Your full name");
      return false;
   }  
}

<table> 
    <form action="insert.php" method="post" name="discover" onSubmit="return disc()">
    <tr><td></td><td><input type="text"  name="name"></td></tr>                                                             
    <tr><td></td><td><br><br><p class="submit"><input type="submit" id="submit" name="commit" value="Register"></p><br><br><br></td></tr>
    </form>
</table>