I have a table with 3 fields [ID, Name, LastUpdated].
LastUpdated has a default value of \"GetDate() so it automatically fills itself when a new record is added.
CREATE TRIGGER dbo.refreshModifyDate
ON tStoreCategoriesImages
FOR INSERT, UPDATE
AS
BEGIN
SET NOCOUNT ON;
update t set t.ModifyDate = getdate() from tStoreCategoriesImages t
inner join inserted i on i.ID = t.ID
END
GO