Add a command button. For more information about adding command buttons, see How to: Create Command Buttons.

Set the PushAction property of the command button to RunObject.

Set the RunObject property of the command button to the name of the form that you want to launch. Because you can use RunObject to run any object, you must specify the type of object, such as Form or Codeunit. You can choose the object from the lookup list provided (in this case, the type of the object is inserted automatically).

Set the RunFormLink property to establish the link to the form that you want to launch. Use the assist-edit button to create the expression. In the Field field, select a field from the form source table. In the Type field, select FIELD as the type of relationship. Finally, in the Value field, select the field from the source table that triggers the current form. This field must match the field that you selected from the source table earlier.