I have now rewritten the js code, but still have same problem. So its not the js. 

var countryselected = "";

$(document).ready(function() {
$("#ddl").change(function()
{
var strSelected = "";
$("#ddl option:selected").each(function()
{
strSelected += $(this)[0].value;
});

countryselected = strSelected;
var url = "/Dinners/mydll/" + countryselected;

sendit(url);

});

function sendit(url)
{
$.post(url, function(data) {});
}
});

I still think its the routing thing