# Select functions

When you click the Functions button in the Expression editor it opens the Function Selection dialog box, listing all the functions available to the Expression editor.

## To select a function for the expression you are creating

1. Click the Functions button.
2. Click a category in the Functions Category list on the left.
3. From the Choices within Category list, double-click the function you want for the expression, or highlight it and click OK. The function is copied to the Expression dialog box.

## See also

Quick reference to math functions

Math functions in expressions

Quick reference to security functions

About expressions