onValueChange.js

import("system.vars");
import("system.vars");
import("KeywordRegistry_basic");
import("DocumentTemplate_lib");

vars.set("$field.REPLACEMENTNAME", null);

if (vars.get("$local.value") != $KeywordRegistry.documentTemplateTypeCategory$htmlTemplate() && vars.get("$field.KIND") == $KeywordRegistry.documentTemplateType$textModular())
{
    vars.set("$context.currentTemplateType", DocumentTemplate.types.TXT);
}