[jQuery] autocomplete plugin not working in firefox

I'm using the autocomplete plugin. The following script works in IE,
but doesn't work in Firefox. It doesn't appear that these are even
being triggered. So when the page displays in Firefox, the
searchStudents textbox has no autocomplete associated with it.

$(document).ready(function() {
$('#searchStudents').autocomplete('<%=Url.Action("Students",
"Student")%>', {
dataType: 'json',
parse: function(data) {
var rows = new Array();
for (var i = 0; i < data.length; i++) {
rows[i] = { data: data[i], value: data
[i].LastName, result: data[i].LastName };
}
return rows;
},
formatItem: function(row, i, n) {
return row.LastName + ' - ' + row.UserId;
},
width: 300,
mustMatch: false,
limit: 10
});

$('#searchStudents').result(function(event, data, formatted) {
if (data)
$(this).parent().next().find("input").val(data
["UserId"]);
$('#Students).append('<option value=' + data["UserId"] +
'>' + data["LastName"] + '</option> ');
});

$('#deleteStudents').click(function() {
$('#Students :selected').each(function(i, selected) {
$(selected).remove();
});
});
});