# Add Fields

This tab allows you to add new fields to the source record. These fields can be used for storing results of calculations in the next step, or given an initial value now using Inaport expressions. They can then be mapped to target fields.

The Field Name is a user-defined name, and the Initial Value Expression can be created using the Expression Editor.

To create a new field:

1. Click the "Add" button to add a row to the grid
2. Double click in the left column, and enter a name for the field
3. Optionally, click on the "..." in the right column and enter an expression. This expression will be evaluated and the result paced in the new field.

### Examples:

If you want to create a new field to be populate with an expression later on, then leave the Initial Value Expression Blank. For example, to create a "Contact" field with no initial value:

Field Name | Initial Value Expression
--- | ---
Contact |

If you want to split up a name field in the source data to first name and last name, then you can input the following:

Field Name | Initial Value Expression
--- | ---
First Name | fname(#Name)
Last Name | lname(#Name)

fname() and lname() are functions accessed by the Expression Editor. For more information on using the Expression Editor, see Using the Expression Editor

Click on the 'Update Preview' button, to see the source data displayed.

The three tabs at the base of the screen allow you to set your preferences for preview control, view the source records and view the modified records. In this case the modified records will show the newly added fields, populated with the relevant data.