compatibility error from 1.2 to 1.3

compatibility error from 1.2 to 1.3

hello to everyone i'm in trouble running my slider panel script i developed in jquery 1.2...it dosen't work under jquery 1.3.2

can someone help me find the error and fix it?

this is the javascript

(document).ready(function() {      
    $(".topMenuAction").click( function() {
        if ($("#openCloseIdentifier").is(":hidden")) {
            $("#slider").animate({
                marginTop: "-121px"
                }, 500 );
            $("#topMenuImage").html('Panel <img src="images/propagator_slider_panel_open.png" alt="open"  class="user_panel-icon" />');
            $("#openCloseIdentifier").show();
        } else {
            $("#slider").animate({
                marginTop: "0px"
                }, 500 );
            $("#topMenuImage").html('Panel <img src="images/propagator_slider_panel_close.png" alt="close"  class="user_panel-icon" />');
            $("#openCloseIdentifier").hide();
        }
    }); 
});