hi everyone, i want some help, i don't know why a modal dialog that i'm creating, is closing without the user button click. what i'm doing wrong?

this is the code of my modal dialog. thanks

$('#dialog').dialog({

autoOpen: false,
width: 400,
modal: true,
resizable: false,
buttons: {
"Ok": function() {
document.formAnLinea.submit();
$(this).dialog("close");
},
"Cancelar": function() {
$(this).dialog("close");
}
}
});

$('form#formAnLinea').submit(function(e) {
e.preventDefault();
$("p#dialogo-detalle").html("Linea: " + $("input#tbLinea").val() + "</br>" +
"Codigo Lista: " + $("input#tbCodigoLista").val() + "</br>" +
"Fecha Validez: " + $("input#tbFecha").val() + "</br>");
 $('#dialog').dialog('open');
});
});


<div id="dialog" title="Verificar Borrado de Linea">
        <p><span class="ui-icon ui-icon-alert" style="float:left; margin:0 7px 0 0;"></span> Desea eliminar la linea del pedido numero: </p>
        <p id="dialogo-detalle"></p>
        <p>Si la informacion es correcta click en Ok.</p>
        <p>Para cambiar, click en  Cancel.</p>
    </div>