ruby on rails redirecting to old param -

i have option user update username in profile. however, when url profile has been set localhost/user/username , when submit changes, redirected old username (not new updated one).

here update users_controller.rb

any suggestions?

 def update     @user = user.find_by_username(params[:id])     @page_title = "edit profile"     respond_to |format|       if @user.update_attributes(params[:user])         format.html { redirect_to(user_url,           :notice => "your profile has been saved.") }         format.xml  { head :ok }       else         format.html { render :action => "edit" }         format.xml  { render :xml => @user.errors,           :status => :unprocessable_entity }       end     end   end 

also, i'm using

def to_param       username   end 

doesn't user_url take @user argument? how have defined route that?

one thing can think of @user.reload!.