function openDir( form ) { 

	var newIndex = form.fieldname.selectedIndex; 

	if ( newIndex == 0 ) { 

		alert( "Please select a product!" ); 

	}
	
	else if (newIndex == 1) {
	
		alert( "Please select a kind of Copper.");
		
	}
	
	else if (newIndex == 4) {
	
		alert( "Please select a kind of Brass.");
	
	}
	
	else if (newIndex == 7) {
	
		alert( "Please select a kind of Aluminium.");
	
	}  else { 

		cururl = form.fieldname.options[ newIndex ].value; 

		window.location.assign( cururl ); 

	} 

}