ajax content (post) in a jquery dialog not loading on the second loading of the dialog
===

I have a page where I load a dialog on click of a button:


    function editShowSchedule(emId){
        $(".ui-dialog-content").dialog("close");			
	    var url = "inc/ajax/schedule-editShowSchedule.php?emId="+emId+"&stationId="+<?php echo $stationId;?>;	
	    var container = '<div id="somediv" title="Modifier l\'horaire d\'une émission"></div>';
	    $(container).load(url).dialog({
		   //modal:false,
		   height: 600,
		   width: 600,
		   resizable: false,
		   buttons: { "Annuler": function() { $(this).dialog("close"); },
				   "Sauvegarder": function(){ saveShowSchedule();} }
	    });
    }


Then, in that dialog, I trigger  .change() on my drop down box to load the infos relative to the selected element.

    <?php 
    $emId = $_POST['emId'];
    $stationId = $_POST['stationId'];
    ?>	
[...]

    $(document).ready(function() {	
	$("#selectShow").unbind('change');
	$("#selectShow").change(function(){
		$("#showTimelines").html('En chargement');
		var emId = $("#selectShow").val();
		var stationId = <?php echo $stationId;?>;
		var params = {emId:emId,
					  stationId:stationId}
		$.post('inc/ajax/schedule-getAllTimelinesByEmId.php',params, function(data){ 
				alert('getTimelineByEmId');
				$("#showTimelines").html(data);				
				$(".button, button, input:submit, input:button").button();	
				enableAddRecurrenceInPeriod();
				enableRecurrenceCloseBox();
			},"html"  
		); 
	})<?php if($emId > 0){?>.change()<?php }?>;
    });


The first time around, it works fine. 

But if I close the dialog box and just click to open it again, then the alert actually works, but I see nothing appearing in the $("#showTimelines").html (not even the loading message:$("#showTimelines").html('En chargement');), even though I do see it in firefox and I made the post only after the document is loaded...

Anybody knows why and/or how to fix this?
