Starting in 2004, an automatic spellchecking can be activated in an enterable field or variable. This feature is native in 4D 2004. Therefore, you don't need any external or plug-ins to enable this feature.
To enable the automatic spellchecking, choose the field or variable object on the form and check the checkbox for Auto Spellcheck under Entry setting in the Property Lists. You can also use perform the manual spellchecking by execute the command SPELL CHECKING. This command will check the spelling of the enterable object where the cursor is.