javascript密码强度提示

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Default.aspx.cs" Inherits="PasswordStrong._Default" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >

<head runat="server">

<title></title>

</head>

<body>

<form runat="server">

<div>

<input name="reg_passwd__" value="" ;="" onkeyup="update_strength('reg_passwd__','reg_passwd__strength_display__')" autocomplete="off" type="password"/>

<script type="text/javascript">

function update_strength(input_field_id, output_display_id)

{

var input_field = document.getElementById(input_field_id);

var output_display = document.getElementById(output_display_id);

var input_str = input_field.value;

var input_length = input_str.length;

var strength = 0;

// increase strength if contains [0-9]

number_re = new RegExp("[0-9]");

if (number_re.test(input_str)) {

strength++;

}

// increase strength if contains non alpha

non_alpha_re = new RegExp("[^A-Za-z0-9]");

if (non_alpha_re.test(input_str)) {

strength++;

}

// increase strength if contains upper case

upper_alpha_re = new RegExp("[A-Z]");

if (upper_alpha_re.test(input_str)) {

strength++;

}

// increase strength if long enough

if(input_length >=8) {

strength++;

}

var strength_str;

if (strength <= 1) {

strength_str = '<strong >弱</strong>';

} else if (strength <= 2) {

strength_str = '<strong >中等</strong>';

} else {

strength_str = '<strong >强壮</strong>';

}

if(input_str.length < 6) {

strength_str = '<strong >太弱</strong>';

}

output_display.innerHTML = strength_str;

}

</script>

<div>

<span>密码强度: </span>

<span >

</span>

</div>

</div>

</form>

</body>

</html>