I still don´t know sh* about mel after all. thx for taking your time skywola. what I wanna do is to toggle Isolate Select but it just wont work. I don´t want to toggle xray. I once copied the first script from the topic Maya tips & tricks from this site. tried to find it again but it´s gone.. don´t quite know where the xRay line came from. did a lot of copy and paste to get this working.

tried your suggestion of code and found out that maya on my machine still has the a problem. now nothing is isolated - means everything gets hidden. by now I believe its something with my installation files.