Absolutely, first you click on start then click on your browser (either Firefox, Opera, Safari, IE) Then click the address bar so the text is highlighted. Now press the delete key.
The next step is to type the following text exactly as I have it here w w w . g o o g l e . c o m In all seriousness, there are thousands of beginning PHP tutorials online, some of the easiest and most concise are at www.w3schools.com
As ShawnCplus has suggested, learn the basics of php programming. The basic working of Login and logout script is simple. A login script takes username and password as input, check the table if the username with that password exists. If yes, then add the username to the session and redirect him to another page. This whole operation is 'login' operation. Logout script is very simple. Just destroy the set session variable and redirect the user back to login page.
Best of luck!