1. variable vs object Read pgs.8.11-8.14 on variables
Read pgs on objects: object names and properties

2. A selection list object
Read pgs ,
refer to the function placeorder() in jackson.html
document.form_name.list_name.selectedIndex
document.form_name.list_name.options[#].text
e.g., document.order.Product.selectedIndex
document.order.Product.options[i].text

3. A radio button object Read pgs.6.28-6.31, 9.29-9.32
document.form_name.button_name[#].length
document.form_name.button_name[#].checked
e.g., document.order.USE[3].checked

4. A check box object Read pgs.6.33-6.35, 9.33-9.36
document.form_name.button_name.checked
e.g., document.Registration.brkfst.checked