You can also calculate out the length of the label.  Something like:

function Print()
{
     var len = 10;
     var msg = "";
     for (var i = 0; i

Hi Guillermo,
We tend to recommend something a little different than line mode, as we don't really support it anymore on the GX printers.  Try sending each line like this:
^XA^MNN^LL30^A0N,25,25^FDThis is going to be^FS^XZ
^XA^MNN^LL30^A0N,25,25^FDa long sentence^FS^XZ
^XA^MNN^LL30^A0N,25,25^FDthat will print one^FS^XZ
^XA^MNN^LL30^A0N,25,25^FDline at a  time.^FS^XZ