elements | NN 2 IE 3 DOM n/a
A collection of all elements contained within a form. Collection members are sorted in source code order. Internet Explorer lets you use array notation or parentheses to access a single element in the collection. Because each form element includes a type property (starting with Navigator 3 and Internet Explorer 4), scripts can loop through all elements in search of elements of a specific type (e.g., all checkbox elements).
Object Model Reference
NN | document.forms[i].elements[i] document.formName.elements[i]
IE | document.forms[i].elements(i) document.formName.elements[i]

length | NN n/a IE 4 DOM n/a
| Read-only
Returns the number of elements in the collection.
Example
    var howMany = document.forms[0].elements.length
Value Integer.