js表单提交,判断文本框,用户名密码是否为空,JS表单检测!

时间:2021-04-08 13:29:53
当表单提交时先触发验证的js代码,当验证表单的方法返回true时才会提交表单返回false则不提交数据
<script type="text/javascript">
function checkIP(){//js表单验证方法
   var text=document.getElementById("url").value;//通过id获取需要验证的表单元素的值
   if(text==""){//当上面获取的值为空时
     alert("不能为空哦!");//弹出提示
     return false;//返回false(不提交表单)
   }
   return true;//提交表单
}
</script>
<FORM METHOD=POST ACTION="" name="ipform" onsubmit="return checkIP();">
<!--使用onsubmit方法进行表单验证-->
<input type="text" id="url" name="ip" size="15" maxlength="50" value="" />
<input type="submit" name="button" value="查询" /></FORM>

定义和用法

onsubmit 事件会在表单中的确认按钮(type="submit")被点击时发生。

dopost方法部分修改

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" 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req.setCharacterEncoding("utf-8");
res.setContentType("text/html;charset=utf-8");

必须放在dopost()方法的第一行

在添加charset=utf-8到res.setContentType中