登录脚本：将用户输入与数据库中已有的数据进行比较

When an user enters in a username and password, i am trying to compare this user input with data that is already stored in the database. For the purposes of just trying to get it to work, if the correct username and password are entered the screen should display "Yay" otherwise it should display "No". When an user enters in a username and password,