problem when empty string is being passed to update_attributes

Hi,

I have the following problem: I have a page where users can update their passwords. When users just leave the password and password_confirmation fields blank, rails will not raise an error when I do

@user.update_attributes(params[:user])

Instead, rails will just leave the record as it is. My guess is that empty fields in the params[:user] hash are just being ingored when calling update_attributes. Any idea how to get around that? I'm sure it's really easy but I have no idea how to fix that

thanks, Marc

thanks