Q:i have a general problem ,,when i wanna to do some thing and i find the jquery file which can do exactly what i wanna to do .. after a while i need another case and i find that another jquery file serve me and fix my problem .. after i add set of jquery files i find conflicts among those files and some features does not work or work in awkward manner ..and when i try to find which file exactly the source for those problems i find myself in closed circle cannot modify this file or cannot delete this file or cannot find that file itself at all ..sometimes the file like this:: <script src="http://jqueryjs.googlecode.com/files/jquery-1.3.js" type="text/javascript"></script> cannot modify it.. the problem has many faces ,, and i cannot really know how to handle the whole matter from the beginning... can any one give me instructions ,, advices,, notes, or explanation to prevent the problem from the beginning and how to fix it if it was happened..