https://webdesign.tutsplus.com/essential-cheat-sheet-convert-jquery-to-javascript--cms-35633a https://www.geeksforgeeks.org/how-to-convert-jquery-to-javascript/
https://andrewlock.net/adding-client-side-validation-to-aspnet-core-without-jquery-or-unobtrusive-validation/ https://github.com/haacked/aspnet-client-validation
