gistfile1.rb

def update
  @subject = Subject.find(params[:id])

  respond_to do |format|
    if @subject.update_attributes(params[:subject])
      flash[:notice] = 'Subject was successfully updated.'
      format.html { redirect_to(@subject) }
      format.xml  { head :ok }
    else
      format.html { render :action => "edit" }
      format.xml  { render :xml => @subject.errors, :status => :unprocessable_entity }
    end
  end
end