Welcoming Visitors to your Site
With a small site of only a couple of pages or so, welcoming people to your site is easy. Just about all of your visitors will entry the site through your home page and you can easily incorporate a welcome message into the page.
When your site has hundreds of pages containing popular information then many of your visitors will be locating pages of specific interest to them using search engines or links from other sites and may not go anywhere near your home page. So how can you welcome them to your site when you don't know what page they will use to enter your site? Including a welcome message on each page of your site would be one solution but this would become annoying to those visitors traversing the many pages of your site who have already seen the welcome message on a previous page.
The answer is to use a javascript to test if this is the first page that the visitor has reached on your site and to display the appropriate welcome message only when this is the case.
Assuming that the pages of your web site are all located on the one server then the full address of each page will all start with the same domain name. If you are not using your own registered domain name then the pages will also all be located within the specific directory that the domain owner allocated for your use. Using javascript, we can access the full address of the current page by reference to location.href.
Assuming that you haven't forgotten the address of where you have loaded your web site, this field doesn't really help much in determining whether the visitor has just entered your site or has just come from another page within your site. To work this out we need the address of the page that the visitor has just come from. Fortunately, Javascript has access to the full address of this page as well by reference to document.referrer.
If you have your own domain name (for this example, let's assume its www.xyz.com) then the following code will extract the appropriate number of characters from the address of the previous page (in this case 11 - the length of www.xyz.com) and test if that previous page was located on your site.
var ref = document.referrer;
var refdir = ref.substring(8);
refdir = refdir.substring(0,11);
if (refdir != 'www.xyz.com') {
// code here executes if previous page was not on this site
}
With this code, the first line loads the address of the previous page into a field with a much shorter name (to make it easier to reference), the second line strips the http://from the front of the address, and the third statement removes the surplus characters from the end of the address leaving the name of our domain if the previous page was on our site and the corresponding part of the address if it wasn't. We can now compare this with our domain name to determine if this is the first page on our site to be visited.
The only changes you need to make to this code to use it on your site is to change the domain name from www.xyz.com to your domain name and the length (11) to the length of your domain name. If you are using a sub-domain then you can use the same code but in this instance you need to include the directory name on the end of the domain name in determining what to compare.
So we now have some javascript code that determines if the previous page was on our own site or not. The easiest way to incorporate this into every page is to code this as an external javascript that is called from every page on your site.
The code to display your welcome message goes in place of the comment within the if statement in the code. This code will only be executed on the first page of your site that the visitor arrives at. Unless the visitor uses the back button to return to that page the code will not be executed on any subsequent pages that they visit on your site during this visit.
There are various ways that you might want to greet your visitors. One way would be to use an alert statement to display your welcome message. The visitor would then have to click the ok button to remove your message and commence viewing your site. A less intrusive way would be to use document.writeln statements to embed the welcome message into the page itself. There are numerous other possibilities as to what you may want to incorporate to present to visitors when they first enter your site, its just a matter of incorporating the appropriate code.
