Email validation in php application

[curi444]

How can i improve email validation in the code below?

<?php
$con = mysql_connect("localhost", "root", "");		
		if(isset($_POST['Submit']))
{
$name=$_POST['textfield'];
$address=$_POST['textarea'];
$phno=$_POST['textfield2'];
$emailid=$_POST['textfield3'];
$comments=$_POST['textarea2'];

if(!$con)
{
die('could not connect'.mysql_error());
}
else
{
mysql_select_db("tender");

$sql="INSERT INTO feedback values('$name','$address','$phno','$emailid','$comments')";
if(!mysql_query("$sql",$con))
{
die("error");
}
echo "added";

mysql_close($con);
}
}
?>

[Atli]

Ok. You can use preg_match to check if the email is valid and print an appropriate response based on that.

See http://www.regular-expressions.inf o/ for info on how to construct regular expressions. There are also a LOT of pre-made regular expressions available on the web specifically to verify email addresses (it's a common task), so you may want to look for some of them. (Check out the top comment on the preg_match page, for example.)