function newPuzzle(){
option = options[index];
index++;
label1.text = '';
R = 20;
for (var i = 0; i<option.length; i++){
    labCont[i] = Titanium.UI.createLabel({
    color:'#999',
    text: option.charAt(i),
    font:{fontSize:20,fontFamily:'Helvetica Neue'},
    textAlign:'center',
    height: 20,
    width:20,
    top: 50,
    left: R
});
labCont[i].addEventListener('click', eventLabCont);
win1.add(labCont[i]);
R = R+20;
}};

I have this code, and after 2, 3 times running this function, the app stops to work. But not always on the same index. What should the problem be?