Most likely using Conditional Formatting under the Format Menu
Read the Excel Help
Enter this conditional format for cell A1 & copy
Change the "Cell Value Is" to "Formula is" and enter the following in
the reference section. (either 1 should work)
=NOT(ISBLANK(A1))
or
=A1<>""
Then select what format you want when data is entered eg. Fonts ,
Patterns, Borders etc.
George