*{ margin:0;padding:0;}

.mask{ display:block; background:#000; position:fixed; left:0; top:0; width:100%; height:100%;filter:alpha(opacity=50);-moz-opacity:0.5;opacity:0.5;z-index:999;}
.dialog22{width:807px;height:420px; position:fixed; left:50%; top:50%; margin-left:-401px; margin-top:-255px; z-index:1000;}