293959 Forms and Script Help

I have already created the dbase tables, and submission forms with variables. Now I am confusing myself with good methods for structure and I need some logic help. *********************************************** FORM = Welder_Oil_Change "Date Performed" Add a drop down calendar displaying in m,y,d format when selected that will pass the date variable. Select oil_qty From welders WHERE welder LIKE id_welder (id_welder from current Drop down on form passed to above query) When submitted email results to email_address ************************************************ FORM = Truck and Welder Maint "Date Performed" Add a drop down calendar displaying in m,y,d format when selected that will pass the date variable. QUERY Select df_mfg_air_pres dr_mfg_air_pres dri_mfg_air_pres pf_mfg_air_pres pr_mfg_air_pres pri_mfg_air_pres From equip_maint WHERE id_truck LIKE (id_truck from current Drop down on form passed to above query) Logic Structure Questions and questions about upadating a the fields in the table Boolan passed to mark change then calulate new milage from filed in different table based on the changed current milage of submission. ************************************************ On the from display recommended milage for changing tire and rotating tires once vehicle id is selected. i.e. truck has manufacture recommended tire life. When the tire is changed reset milage to calculate based on current milage plus recommeded milage from differnet table. based on last milage input. i.e. truck has manufacture recommended tire rotation based on current milage calulate recommended tire rotation absed on last milage input. When submitted email results to email_address I am using Mysql 5 and have other questions about PK and SK if I should use or just leave as I already have created the tables.