I'm no PHP expert - I've cobbled my knowledge together from articles, books, etc. My website has worked fine for 4 years but I recently changed hosts and now some of my php scripts aren't working properly. I don't know what my site used to be hosted on, but my test setup on my own PC is XP, Apache 1.3.XX, PHP 4, MySQL 4, etc. My new hosting environment for the live site is Linux and I suspect that might be the problem. I'm not sure if I can be brief and give enough detail, but a few examples are: I use horizontal tabs for some sections of my site. I wrote some code myself to look inside the current directory, determine if a certain php file is present, and if it is then display a tab. The type of tab depends on whether the php page is current or not. If the file doesn't exist in the current directory, then no tab is displayed. This is all achieved by declaring variables using $HTTP_GET_VARS, and then using IF... ELSE, file_exists, case... switch... break, substr_count, PHP_SELF and a function. A second example is a quick and simple browser detect, looking for specific browser agents. The site then displays things differently depending on what it detected as viewing the site. This code also excluded large images from being displayed in the AvantGo PDA offline browser application. Unfortunately, this code now thinks that the main browser is AvantGo and so won't display the large images! This code uses stristr and HTTP_USER_AGENT as well as the usual $HTTP_GET_VARS for variables and again it used to work perfectly... I'm assuming that I need to do some tweaking somewhere (php.ini?) on the server, but have no idea where to start! it's just annoying that code that worked fine before is no longer working as it should. The versions of Apache, PHP, MySQL etc. are close to the ones I have on my test setup, so I'm fairly sure it isn't a PHP4 vs PHP5 kind of issue. Help?