accessing vars of other script doesn't work

Hi guys...

Is it possible to access vars of another script? Yes it is, but one script is js the other script is c#. And it doesn't work. Not even broadcastMessage works.

First try

 var MainScript :main_level;

Second try

 var MainScipt :GameObject;

 MainScript.BroadcastMessage("Set");

has no receiver...!!! the void of the c# script is: void Set(float abstandy){ AbstandY = 100; }