Email validation script in Php

There is simple code to validate email  in php

Php code //

If(trim($_REQUEST("email"])=="")
$Em="Email id cannot be empty";
$errFlag="true";
}
else
{
if(!ereg("^(.+)@(.+)\\.(.+)$",trim($_Post("email"])))
{
$Em="Invalid Email Id";
$errFlag="true";
}
}


Html code //
Email    " size="40" maxlength="40">