JS_ReportError(cx, "%s.prototype.%s called on incompatible %s",
JS_ReportErrorNumber(cx, NULL, JSMSG_INCOMPATIBLE_PROTO,
JS_InstanceOf(JSContext *cx, JSObject *obj, JSClass *clasp, jsval *argv){    JSFunction *fun;    CHECK_REQUEST(cx);    if (OBJ_GET_CLASS(cx, obj) == clasp)	return JS_TRUE;    if (argv) {	fun = js_ValueToFunction(cx, &argv[-2], JS_FALSE);	if (fun) {	    JS_ReportError(cx, "%s.prototype.%s called on incompatible %s",			   clasp->name, JS_GetFunctionName(fun),			   OBJ_GET_CLASS(cx, obj)->name);	}    }    return JS_FALSE;}