To define an Integer Popup attribute:
On the Category page, click Integer: Popup in the Add Attribute drop-down list.
On the Add Attribute To page, type a name for the attribute in the Name field.
In the Rows section, do the following:
Click the name of the attribute after which you want the new attribute to appear on the Category page in the After drop-down list. Click <None> to set the attribute to appear first.
Select or clear the following check boxes:
To set each value that appears in the attribute's popup list, type an integer on each line in the Valid Value field, pressing ENTER after you type each value. Valid values for the integer can range from -2147483647 to 2147483646.
On the Category page, to set a default value for the attribute, click a month, date, and year (and time, if applicable) in the appropriate drop-down lists.