Please how do i rewrite this url: http://www.site.com/members.php?userid=10 to something like http://www.site.com/seyi, so that when it is typed it shows the users profile.
Please help me with detailed infomation i know it has something to do with .htaccess and may be mod_rewrite if am not mistaken. Thank you

While you sort out the mod-rewrite and htaccess thingy, here's what i'm thinking of.

Create a database having the following info.
alias = which in your case will be "seyi". i.e the sub directory after the main domain.
member_id = which for "seyi" will be "10"

both fields must be unique

Now write a script to do the following.

Get the sub directory from a url when a user enters the url. So if the user enters http://www.site.com/seyi, get the "seyi" part of url and store in a variable $alias.

Crosscheck the variable with the list of alias u have in your database. If one row is affected, return the member_id for that row and store as $member_id

then use the php header method to redirect the user

header("Location: http://www.site.com/members.php?userid=".$member_id);


Aight I just wrote this here without testing it so if it works, fine. If it doesnt work 

kohana PHP framework makes this sweet, It supports url rewriting. Move ur app and enjoy!!!!

check http://docs.kohanaphp.com/

A professional way of doing it is to use the url rewriting of apache (if you are using an apache server).
You may enter "url rewriting tutorial" in google and go through the results.

But let me quickly give you some important points:
1. url rewriting will involve you creating a .htaccess file into your site
2. If you are using an offline server like wamp server, you may need to enable url rewriting in your apache config
3. this stuff works on some windows server.

I can answer any of your questions on url rewriting, but your question has to be specific. I dont know the server
you are using, so i cannot solve your question diectly at the moment.

you can make use of .htaccess but pratice locally i have bleeped up a website to that you enable the mod_rewrite engine and you specify what you want which reminds me you need to familair with regular expression e.e(^[a-zA-Z0-9]$) trust me it aint easy then u might have issues with css rendering so u might want to links ur css with the full name e.g http://domain/folder/*.css take care