Best way to write functions in javascript [duplicate]

[AOA7]

I've recently started maintaining someone else's JavaScript code. I'm fixing bugs, adding features and also trying to tidy up the code and make it more consistent.The previous developer uses two ways of declaring functions and I can't work out if there is a reason behind it or not.The two ways are:\[code\]var functionOne = function() { // Some code};\[/code\]\[code\]function functionTwo() { // Some code}\[/code\]What are the reasons for using these two different methods and what are the pros and cons of each? Is there anything that can be done with one method that can't be done with the other?