验证数字，大写字母，小写字母，特殊字符四选三组成的密码强度，且长度在8到30个数之间

表达式：

^(?![a-zA-Z]+$)(?![A-Z0-9]+$)(?![A-Z\W_!@#$%^&*`~()-+=]+$)(?![a-z0-9]+$)(?![a-z\W_!@#$%^&*`~()-+=]+$)(?![0-9\W_!@#$%^&*`~()-+=]+$)[a-zA-Z0-9\W_!@#$%^&*`~()-+=]{8,30}$

js写法：

var regex = new RegExp('^(?![a-zA-Z]+$)(?![A-Z0-9]+$)(?![A-Z\W_!@#$%^&*`~()-+=]+$)(?![a-z0-9]+$)(?![a-z\W_!@#$%^&*`~()-+=]+$)(?![0-9\W_!@#$%^&*`~()-+=]+$)[a-zA-Z0-9\W_!@#$%^&*`~()-+=]{8,30}$');
if(!regex.test(pwd)){
    msgError("输入错误：密码不符合规则，请重新输入。");
    $("#password").focus();
    return;
}