I need as same as it. And website is custom made. Is there pre-code which we can get in google?
If your site was custom made for you then you are largely in the hands of the people who wrote it. Also, I write all my own code, so I do not know whether there are pre-coded complete examples on Google.
In my opinion, even a newbie should be able to adapt my code to their needs with the aid of good HTML/CSS references like W3Schools or the WDG manuals. That way you get to understand what your code is doing, and how to fix it if it goes wrong. However, amending someone-else's code is far more demanding because the learning curve is so much steeper. That is why, in my example I've focussed on the core functionality. So it should be clearer what does what. Whereas a complete example may be far more difficult to grasp as there may be enhancements like graphic icons included in the menu etc... These can be added once the basic code is understood.