var checkRegisterForm = function(){

   // TODO:

    var username = document.getElementById('username');

    var password1 = document.getElementById('password');

    var password2 = document.getElementById('password-2');

   var username_reg = /[0-9a-zA-Z]{3,10}/;

   var password1_reg = /{6,20}/;   

   if(username_reg.test(username.value) && password1_reg.test(password1.value) && (password1.value === password2.value ))

   {

       return true;

   }

   else

   {

      return false;

   }

}