The example in this article describes how to use JavaScript to determine whether a form is empty and get focus. Share it with everyone for your reference, the details are as follows:
<%@ page contentType="text/html; charset=gb2312" language="java" import="java.sql.*" errorPage="" %>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=gb2312">
<title>javascript获得焦点</title>
</head>
<script language="JavaScript">
function aa()
{
if(document.forms[0].elements[0].value.length==0)
{ alert("姓名不可以为空");
document.forms[0].elements[0].focus();
return false;
}
else if(document.forms[0].elements[1].value.length==0)
{ alert("密码不可以为空");
document.forms[0].elements[1].focus();
return false;
}else {return true;}
}
</script>
<body>
<form action="/ok.jsp" method="post" name="form1" onSubmit="return aa();">
用户名<input type="text" name="name" >
密码<input type="password" name="password">
<input type="submit" value="提交">
</form>
</body>
</html>
I hope this article will be helpful to everyone in JavaScript programming.
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