The purpose of the Start operation is to connect to our application by pressing the Enter key. 
- From the Service Interfaces Editor, click Operation > New. 
 
- In the Operation Name field, type Start. 
 
- Leave the default values in the Active Screen and Previous Screen fields. 
 
- In the Transaction ID field, type MFDEMO; then click OK. 
 
- In the Assignments pane, right-click and select New Assignment from the popup menu. 
 
- From the Assign to drop-down list, click ATTENTION ID. This is the field that defines which AID key (for example, Enter, PF8, etc.) should be used. 
 
- From the Field 1/Operand 1 drop-down list, click ENTER. 
 
- Click OK. 
 
- Save the service interface. 
This completes the Start operation.