validating a form

I want to make sure that people are entering valid emails ( atleast with @whatever.com). And i want it to make sure they retyped their email correctly. How do i do that with javascript?

Here is the form im using.

<form name="form2" method="post" action="regcomplete.php">
<p>Name:<input type="text" name="name">
<br>
Email:<input type="text" name="email">
<br>
Retype your Email:<input type="text" name="remail">
<br>
Create a password:<input type="password" name="password">
<br>
<input type="submit" name="Submit" value="Sign me up!">
</p></form>



Thanks alot for whatever help anyone can provide.