Email validation

[eluser]Unknown[/eluser]
Hi all,

I have one problem here.
I just use 'email library class' to validate email address.
But i'm getting error response where function validate_email always return false even I input the right email address.

This is my codes in controller:

$this->load->library('Email');
echo $this->email->validate_email($email);
if ($this->email->validate_email($email))
echo "valid email";
}
else{
echo "invalid email";
}

Can you tell what i'm wrong here?:-)