I have fixed the problem myself, the solution was:
$('table#newspaper-a tr:not(#header, #trWeekNummer)').hide();
if(List[x].selected)
{
$('table#newspaper-a tr:not(#header, #trWeekNummer)').each(function(){
$('td:nth-child(1)',this).each(function(){
if($(this).text() == List[x].value)
$(this).parent(this).show();
});
});
}