Register

Username		*Input 【A-Za-z0-9】，Length less than 20 characters
Password		*Input 【A-Za-z0-9】，Length less than 20 characters
Confirm password		*Input 【A-Za-z0-9】，Length less than 20 characters
Snapshot save dir		*Input correct，Max length 30 Same as：d:/picture/
Record video save dir		*Input correct，Max length 30 Same as：d:/video/

Notice：Confirm the directory exist！