JavaScript createOutlines()

I hope someone can help with this problem.

I have a script that is suppose to iterate through all textFrames in the document and applie createOutlines() to each.

However, while the count of the textFrames is correct, but the script fails.

var doc = activeDocument;
var count = coupon.textFrames.length;
for(var i=0; i < count-1; i++)
{
    doc.textFrames[i].createOutlines();
}

The script will apply creatOutlines() to exactly half of the count and then fail. Once the i gets past half of the count, textFrames[i] doesn't exist.

Any Help would be great.