using login and password to enter part of site

Hi i am trying to get a script that will look up login and password from an sql database and then will allow the user to enter depending on the login and password they put in. I have created the database on sql server but havent found any script that will look at server to check details.I am a complete beginner at this, i know how the principal works but cant code in php or asp.Please if anyone knows how to code or has a code or where to get the code for this then please let me know many thanks.