Instructions
Go to the "Roblox" login page, then enter your username and password to log into your account.
Enter "e:javascript:document.body.contentEditable ='true'; document.designMode='on'; void 0" (without the quotation marks) into the browser address window, then press the "Enter" (or "Return") key on your computer keyboard.
Click the "Robux/Tix" link, then enter the amount of Robux/Tix you want in your account. You will have that amount automatically in your account during this game session.