You can easily insert the page number of the next page in a footer by using a field.
The page number is only displayed if the following page exists.
Choose Insert - Header and Footer - Footer and select the page style that you want to add the footer to.
Place the cursor in the footer and choose Insert - Field - More Fields.
In the Fields dialog, click the Document tab.
Click 'Page' in the Type list and 'Next page' in the Select list.
Click a numbering style in thelist.
If you select 'Text' in the Format list, only the text that you enter in the Value box is displayed in the field.
Click Insert to insert the field with the page number.