Define()

I am developing an app which needs 3 constants. The value of these constants comes from a database result. This works fine. My problem is that they do not work very well. I am developing on both windows/Linux (depending what I boot into). This is the effect I want $doc_dir = the string of d:/is/clients/client/web/store/ $image_dir = the string of d:/is/clients/client/web/images/ $control_dir = the string of d:/is/clients/client/web/control/ define(HOME_DOC_ROOT,$doc_dir); define(IMAGE_DOC_ROOT,$image_dir); define(CONTROL_DOC_ROOT,$control_dir); The outcome is that 1. I cannot submit pages using action="<? echo CONTROL_DOC_ROOT ?>"verify_login.php" 2. I cannot use links as <a href="<? echo $DOC_HOME_ROOT ?>">click here</a> Has anyone had a lot of use with define and in my scenario. I don't the problem is with the db results, I think it's more of the define(). Like I said above, I am using this on linux as well as windows. ========================== Every chance I get, I try to incorporate Open Source resources into my everyday work. Maybe instead of of paying Microsoft for software, the money can added to my salary. ==========================