Please Read Carefully:
Your form page MUST be published as PHP. This is done through View > Page Properties > File Extension (when published).
Many people use the TAB button to move from field to field .
As you add more and more fields in your form, you might need
to set the order in which the TAB button will move the cursor
from field to field.
Here is the 'official way' to change the TAB order of the elements on
an existing form:
Right click the first element of the form and select 'Move to front'
Do this for all your form elements in the order you want the tab to go.