Trouble with Global Variable

I can't retrieved a Global Variable in an EA. First I am setting a Global Variable with a script. Then I am attempting to read the Global Variable in an EA. Here is the code and errors. What is wrong?

script...

int start()
{
   int testVar;
   GlobalVariableSet(testVar, 12345);     // set the global variable
   int xyz = GlobalVariableGet(testVar);  // get the global variable just as a test
   Print("Script: ",xyz);                 // prints: "Script: 12345"
   return;
}

EA...

      int abc = GlobalVariableGet(testVar);  // get variable
      Print("Error: ",GetLastError());       // prints, "Error: 4058". global variable not found
      Print("Result: ",abc);                 // prints, "Result: 0"