From the configuration area of the script, do it like so:
Code:
//Specify display mode. 3 possible values are:
//1) "always"- This makes the fade-in box load each time the page is displayed
//2) "oncepersession"- This uses cookies to display the fade-in box only once per browser session
//3) integer (ie: 5)- Finally, you can specify an integer to display the box randomly via a frequency of 1/integer...
// For example, 2 would display the box about (1/2) 50% of the time the page loads.
var displaymode="oncepersession"
Bookmarks