function checkRegisterForm(){
        var username = document.getElementById("username").value;
        var usernameCheck = /^[A-Za-z0-9]{3,10}$/;
        var check1 = usernameCheck.test(username);
        var password = document.getElementById("password").value;
        var passwordCheck = /\w{6,20}/;
        var check2 = passwordCheck.test(password);
        var password2 = document.getElementById("password-2").value;  
        return check1 && check2 && password===password2;
      }