<html>
<head>
<title></title>
<script language="javascript">
function chk()
{
}
</script>
</head>
<body>
<form name="name" action="" method="post">
<input type="password" name="upassword"/>
<input type="submit" name="submit" value="提交" onclick="chk();">
</form>
</body>
</html>
请问如何用JS判断输入的字符串长度为6到20位
如何判断输入的只是数字和小写字母
<head>
<title></title>
<script language="javascript">
function chk()
{
}
</script>
</head>
<body>
<form name="name" action="" method="post">
<input type="password" name="upassword"/>
<input type="submit" name="submit" value="提交" onclick="chk();">
</form>
</body>
</html>
请问如何用JS判断输入的字符串长度为6到20位
如何判断输入的只是数字和小写字母
<script language="javascript">
function chk()
{
var pwd=window.document.name.upassword.value;
if(pwd.length<6||pwd.length>20){
alert("输入的密码长度不合法");
return false;
}
return true;
}
</script> 这样就OK了
不过调用时最好这样<form name="name" action="" method="post" onsubmit="return chk();">
这个可以
var pp=/^[0-9a-z]+$/;
<html>
<head>
<title> </title>
<script language="javascript">
function chk()
{
var password= document.forms['name'].password;
var patern=/^[0-9a-z]+$/;
if(password.length < 6)
{
alert("密码长度不能小于6");
return false;
}else if(patern.test(password.value))
{
alert("密码为数字与小写字符的组合");
return false;
}
return true;
}
</script>
</head>
<body>
<form name="name" action="" method="post">
<input type="password" name="upassword"/>
<input type="submit" name="submit" value="提交" onclick="chk();">
</form>
</body>
</html>