Fix some issues in slides
Fix some issues in slides

TelerikAcademy/JavaScript-Applications,HomerWork/JavaScript-Applications,Didexe/JavaScript-Applications,HomerWork/JavaScript-Applications,Didexe/JavaScript-Applications,kidroca/JavaScript-Applications,kidroca/JavaScript-Applications,TelerikAcademy/JavaScript-Applications,TelerikAcademy/JavaScript-Applications,Didexe/JavaScript-Applications,kidroca/JavaScript-Applications,HomerWork/JavaScript-Applications