Hello i am new to MySQL, i have created a registration form for my website now i am making the login.

By making the registration form i have learned how to use mySQL's insert function. I need the login form to on submit take the username the user entered and from that retrieve the password from the database. It should then match up the server retrieved password with the one the user supplied to see if the user entered the correct username and password. I am guessing i will need to use mySQL's Where. How do i do this?

Here is the code for the form:
Code:
<h3 align="center">Login</h3>
<br />
<br />
<div align="center">
<form action="login.php" method="post">
<b>Username:</b>
<br /><input type="text" name="username">
<br />
<br />
<b>Enter your Password:</b>
<br /><input type="password" name="password">
<br />
<br />
<input type="submit" value="Login">
</form>
</div>