checking for name + password in a row

[bike5]

Im using mysql.
I made a form to create a user name and password, and thats works, and I crytped the password. Now I made a form to log in and I don't know how to get the name and password checked to see if they exist. But only if both exist in the same row, well you know how a login thing works right? If anyone could give me an example of how to check for the name and password that would be great. I used
$user_name
$user_password
and my table has a
user_id which is set to auto increment.

Thanks for your help in advance.

[Anon]

A simple one would look something like this..

//build the query to check for both values
$sql ="select * from table where user_name = '$user_name' and user_password = '$user_password'";

// connect to the DB server and select a DB
mysql_connect ("my.host.com","mysql_username","mysql_password");
mysql_select_db ("my_database");

// execute the query
$result=mysql_query($sql);

// check result resource
if ($result) {
echo "valid";
} else {
echo "not valid";
}

This is a simple example, you would need to encrypt the password before passing it to the query, and do validation on the data in general.