def add_format(property_hash = {})
      properties = {}
      if @excel2003_style
        properties.update(:font => 'Arial', :size => 10, :theme => -1)
      end
      properties.update(property_hash)

      format = Format.new(@formats, properties)

      @formats.formats.push(format)    # Store format reference

      format
    end
def add_format(property_hash = {})
      properties = {}
      if @excel2003_style
        properties.update(:font => 'Arial', :size => 10, :theme => -1)
      end
      properties.update(property_hash)

      format = Format.new(@formats, properties)

      @formats.formats.push(format)    # Store format reference

      format
    end
The +add_format+ method can be used to create new Format objects
 which are used to apply formatting to a cell. You can either define
 the properties at creation time via a hash of property values
 or later via method calls.

     format1 = workbook.add_format(property_hash) # Set properties at creation
     format2 = workbook.add_format                # Set properties later

 See the {Format Class's rdoc}[Format.html] for more details about
 Format properties and how to set them.