Datatable not showing header after displaying a hide table

Hello,

I have a table in my html page:

<

table id="mainTable" class="table table-striped center" style="display:none"> when the table is loaded I show them with:

fnInitComplete: function () {
$('#mainTable').show();
}

But header is not visible, i cheked the html and it generate another table without id that constains the style="display:none" for the header.