Can i add two or three ajaxcontroltoolkit tool into toolbox??

Question

hello everyone! I have a question that i want to add more once ajaxcontroltoolkit into my toolbox and how to declare in web.config and "Bin" folder?Because when i try to add 2 or 3 ajaxcontroltoolkit with 3.5 or 3.0 version.Sometimes i see it have some problem.Give me a advice!Thanks so muck.