function sendRequest(url, form) {

    url = contextPath + "/" + url;

    dojo.debug("url=" + url);
    dojo.io.bind({
        url: url,
        formNode: form,
        preventCache: true,
        load: function(type, value) {
            dojo.widget.byId("maindiv").setContent(value);
        },
        error: function(type, value) {
            alert("Unknown Error!");
        }

    });
}