The reference, lookup, and information functions really shine when you want to build worksheets that automatically carry out a series of boredom-inducing tasks. And they let you tie your information together in interesting ways. Maybe you want to determine monthly wages based on billing rates, build a parts list for an order, or create an invoice based on items that have been ordered from a product catalog. This last task, which is shown in the next example, is sometimes called a dynamic invoicer. It lets sales representatives quickly create an invoice by choosing from a catalog of company products.
The dynamic invoicer employs the following techniques:
Looking up information from a table with VLOOKUP().
Avoiding calculations when data isn't present with IF() and ISBLANK().
Referencing data from another worksheet.
Using absolute references to make it easier to copy formulas.
First, you build the table filled with your company's products. Figure 12-9 shows you the list for this example.
Figure 12-9. Here's a product catalog that a sales rep might use to build an invoice. It includes the Product ID (used for the lookup), the Model Name (used to identify the selected products), and the Price (used to calculate the total cost of an order).
Next, you build a worksheet that actually creates the invoices. You should probably include space for ...