Obsolete since JSAPI 26
This feature is obsolete. Although it may still work in some browsers, its use is discouraged since it could be removed at any time. Try to avoid using it.
Every instance of JSBool has been replaced by bool. JS_TRUE has been replaced by just true and in the same way JS_FALSE by false.
JSBool is the return type of many JSAPI functions and callbacks. JS_TRUE indicates success; JS_FALSE indicates an error or exception occurred.
JSBool is an integer type. JS_TRUE is (JSBool) 1 and JS_FALSE is (JSBool) 0. These values must not be used as jsvals. Instead, use JSVAL_TRUE and JSVAL_FALSE, and use BOOLEAN_TO_JSVAL and JSVAL_TO_BOOLEAN to convert.