This error usually shows up when the reference to the jQuery library is missing.
Verify if the file path is correct. One way to check this is by trying to access that file as a URL. For example, if your application URL is http://localhost/myapp check if http://localhost/myapp/jquery-1.7.2.js loads
fine.
M.V.'Anil' Radhakrishna
Web Development Tips, Tricks & Trivia