Cannot Move Focus To Control - Not Enabled

The following function() works fine on Chrome and Firefox but Internet F*C*I*G Explorer is showing a warning: Can't move focus to the control because it is invisible, not enabled, or of a type that does not accept the focus. This function only load a few data into a SELECT, just that.

Code:
function cargarCanales() {
var ciudad = document.getElementById("ciudad").value;
var startTime = "<?php echo $startTime; ?>";
var endTime = "<?php echo $endTime; ?>";
cantCanales = getCanales(ciudad,startTime,endTime);

Up here works fine. If I check cantCanales with "alert" function I get a normal value.
for (i = 1; i <= cantCanales; i++) {
canal.options[i]=new Option(i, i);
}

Here everything is stopped, so I think that may be the problem is the "FOR" but how I said, on Chrome and Firefox everything works fine.
$("#canal").attr("disabled",false);
}
My SELECT.:
Code:
<select id="canal" name="canal"><option value="0">Select Channels..</option></select>

I call the function cargarCanales() from here:
Code:
$("#ciudad").change(function(){cargarCanales();});
When the select CIUDAD change, the cargarCanales function loads..
The full error message : [URL]