Nested For Each X element in Array

I'm trying to recreate the code below in Construct 2. I think I have most of it correct, but the stop loop doesn't seem to work.

var array1 = new Array("a" , "g" , "e" , "j" , "a");

var array2 = new Array("b" , "a" , "c");          

for each (var letter in array2) {

for (var i=0; i < array1.length ; i++) {

    if (letter == array1(i)){

        array1(i) = -1;

        break;

     }

}

trace(array1);

// OUTPUT: is -1,g,e,j,a

When the loop finds the first letter 'a' it changes it to '-1', but stops and doesn't change the last 'a'. In Construct the output is -1,g,e,j,-1. The only thing I can think of is that I'm not implementing the stop loop properly.

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