Search Engine can generetad your site content via your sitemap. If you are not having sitemap.xml for your site the you probably get code from Google Code Sitemap Generator.
Automatic Ping to Google
http://www.google.com/webmasters/tools/ping?sitemap=WWW.YOUR-SITE.COM/SITEMAP.XMLMicrosoft Bing Automatic Ping
http://www.bing.com/webmaster/ping.aspx?siteMap=WWW.YOUR-SITE.COM/SITEMAP.XML
Automatic Ping Yahoo
http://search.yahooapis.com/SiteExplorerService/V1/ping?sitemap=WWW.YOUR-SITE.COM/SITEMAP.XML
Ping Ask.com
http://submissions.ask.com/ping?sitemap=WWW.YOUR-SITE.COM/SITEMAP.XML
ping morever
http://api.moreover.com/ping?sitemap=WWW.YOUR-SITE.COM/SITEMAP.XML
If you are Using *Linux Server *
2. Edit the file with your sitemap URL.
3. Upload that file in your sites root folder.
4. Now log on to your Control Panel.
5. Find an Option for Create Cron Job.
6. Define Cron Job as per your site requirement, Daily, Weekly, Every
1 Hour etc.
7. Select ping.php as schedule file.
If you are using *Windows Server* then check this:
You can do this in task scheduler of windows server. Task can be created manually in the task scheduler or with @ commands and can be designated to run under a user account with privileges. There is also a software (free) called nnCron which uses the same kind of syntax that of Linux on Windows.