[jQuery] Dialog (jQuery UI Dialog) closes when i cancel a form submission

[iceangel89]

i have a form inside dialogs. i use ajaxForm plugin for my forms. i
validate using beforeSubmit ... like in the example below. the strange
thing is the dialog closes in the Add/Edit Type forms but not in the
Add/Edit Category. the form did not submit which means the return
false works but the dialog containing the form closes. why is this so?

$("#frmAddType").ajaxForm({
    dataType: "json",
        beforeSubmit: function() {
                if ($("#atName").val() == "") {
                        alert("Please enter a type");
                        return false;
                }
        },
    success: postAddType,
    resetForm: true
});
$("#frmEditType").ajaxForm({
    dataType: "json",
        beforeSubmit: function() {
                if ($("#etName").val() == "") {
                        alert("Please enter a type");
                        return false;
                }
        },
    success: postEditType,
    resetForm: true
});
$("#frmAddCategory").ajaxForm({
    dataType: "json",
        beforeSubmit: function() {
                if ($("#acName").val() == "") {
                        alert("Please enter a category");
                        return false;
                }
        },
    success: postAddCategory,
    resetForm: true
});
$("#frmEditCategory").ajaxForm({
    dataType: "json",
        beforeSubmit: function() {
                if ($("#ecName").val() == "") {
                        alert("Please enter a category");
                        return false;
                }
        },
    success: postEditCategory,
    resetForm: true
});
});