Pop-Up Window JavaScript
First, copy and paste the code below under the <body> tag of your web page. The <body> tag will appear something like this: <body bgcolor="#FFFFFF" text="#000000">
Second, in the <body> tag itself enter in this line of code: onunload="checkCount()"
This is how the <body> tag should look after you have that line installed:
<body bgcolor="#FFFFFF" text="#000000" onunload="checkCount()">
Third, look at the line that says: var expDays = 1; // number of days the cookie should last. Here you can change the "1" to any number you want. So for example, if a visitor visited your site the first time and your pop-up window appeared if they came back anymore times that same day the pop-up will now appear, but the next day if they come back the pop-up will appear again. If you set the number to 20, the visitor will not see the pop-up again for another 20 days after the first time they see it. You get the idea.
Forth, change the "popup.htm" to the name of the page that you uploaded on your server that contains the contents you want to appear in the pop-up window. This line is right below the "var expDays" line I talked about above.
Fifth, right under the "var page" line is the "var windowprops" line, here you can change the height and width of the pop-up window in pixels. You can also change the any of the "no" to "yes". It's pretty self-explanitory.
That's it! Upload the page with the script and the page with the pop-up contents and you're ready to roll. Don't forget to test it out. If the window keeps popping up make sure you have cookies enabled in your browser.