jQuery Grid Plugin - jqGrid

Hello,

I have an error and I don't anderstand why?

Erreur : object is undefined
Fichier Source : http://its001wdev/bibliotheque.....y-1.3.2.js
Ligne : 672

This error appears when I want to do multiple search or use this:

    $("#parametre_serveur").click( function() {
        var pd =$("#liste_menu").getPostData();
        var r ="";
        $.each(pd,function(i){ r += i+": "+pd[i]+","; })
        $("#postdata").html(r).css("background-color","yellow");
    });

Do you have an idea. I use jqgrid3.5 and it doesn't work with IE6 and firefox.

Thank you for your help.

Regards.

Missa