search for: new_total_weight

...ion, { :precision => 4 }).to_s + "'';" The controller code is as follows in the update_totals method which is called via the observe_field : if @comm_type == "L" @new_total_commission = @new_total_sell.to_f * @converted_rate.to_f else @new_total_commission = @new_total_weight.to_f * @converted_rate.to_f end Outputting debug to the log file shows that the @new_total_commission is being set correctly. The debug information in the browser window for the RJS "trick" produces the following: (''total_commission_3407'').value=''$210.0000'...