Javascript perfect random ad code

If you need to randomly display images or links to Banner in your home page, how can you achieve this?
Below is a random display of five Banner'sCodeYou can define it yourself.
Code:

Copy code The Code is as follows: <script language = JavaScript>
VaR M = 5; // Several banners are randomly displayed.
VaR n = math. Floor (math. Random () * m + 1)
Switch (N)
{
Case 1:
Document. Write ('banner1 HTML ');
Break;
Case 2:
Document. Write ('banner2 HTML ');
Break;
Case 3:
Document. Write ('banner3 HTML ');
Break;
Case 4:
Document. Write ('banner4 HTML ');
Break;
Case 5:
Document. Write ('banner5 HTML ');
Break;
}
</SCRIPT>

What if the corresponding connections need to be added to some advertising images? The Code remains the same:

Code:
[Ctrl + A select all Note: If you need to introduce external JS, You need to refresh it to execute]