function toggle_sign_in(){
	var sih = document.getElementById( 'sign_in_holder' );
	var sil = document.getElementById( 'sign_in_lnk' );

	if( !sih || !sil )
		return false;
	
	if( sih.style.display != 'block' ){
		sih.style.display = 'block';
		document.getElementById('email').focus();
	} else {
		sih.style.display = 'none';
	}
	sil.innerHTML = ( sil.innerHTML == 'Sign in' ) ? 'Cancel' : 'Sign in';
}