Jquery hide is not working in my Dialog box close span

$('.ui-dialog-titlebar-close ui-corner-all').hide();

this is the hide for my Jquery dialog close 'X' span.. this is not working in my case.

I am trying to hide that Close becuase its not showing me in my dialog when 开发者_StackOverflow社区I resize my dialog then its showing me.. some reason my CSS not showing me that Close button correctly on my POPUP.

Can any body help me out.

here is my code and CSS.

  $("#window").dialog({
          resizable: true,
          height: 180,
          title: titles,
          width: 500,
          modal: true,
          open: function () {
              $('.ui-widget-overlay').show();
              $('.ui-dialog-titlebar-close ui-corner-all').hide();
          },
          buttons: {
              "OK": function () {
                  $(this).dialog("close");
                  if (redirectURL) {
                      window.location = redirectURL;
                  }
              }
          }
      });

here is my CSS.

<style>
.ui-widget-overlay {
    background: black;
    opacity: 0.5;
    filter: alpha(opacity = 50);
    position: absolute;
    top: 0;
    left: 10;
 }
</style>

Can any body tell me how to show My Close 'X' correctly on my dialog or I need to hide that Close 'X'

thanks

The selector for multiple CSS classes has a full stop between the two, like this:

$('.ui-dialog-titlebar-close.ui-corner-all').hide();