//add thickbox to href & [color=#FF0000]area elements that have a class of .thickbox[/color]
function tb_init(domChunk){
    $(domChunk).click(function(){
    var t = this.title || this.name || null;
    var a = this.href || this.alt;
    var g = this.rel || false;
    tb_show(t,a,g);
    this.blur();
    return false;
    });
}

[<a href="javascript:void(0)" class="preview">预览</a>]

var aLink = document.getElementsByTagName('a');
    var nLinkCount = aLink.length;
    for (var i = 0; i < nLinkCount; ++i) {
        if (aLink[i].className == 'preview') {
            aLink[i].onclick = function() {
                ajax_request('share_action.php?action=preview', function() {
                    try {
                        eval('var oRet = ' + arguments[0].responseText + ';');//返回的参数
                        share_create_iframe('preview_qq_share', g_sMengluInterfaceUrl + '?action=preview&time=' + oRet.time + '&token=' + oRet.token);
                    }catch(e) {
                        alert('预览失败');
                    }
                }
                );
                
                
                return false;
            }
        }
    }

function ajax_request(sServerUrl, fnCallback, bSync, oPostParam, vCallbackParam) {
    var oHttpRequest = new window.XMLHttpRequest();
    if (!bSync) {  //确定是同步还是异步 
        _set_onreadystatechange(oHttpRequest, fnCallback, vCallbackParam);
    }
    if (oPostParam) { //处理post方法所传递的参数 形式以&&&累加
        var a = [];
        for (var s in oPostParam) {
            a.push(s + '=' + oPostParam[s]);
        }
        var sPostParam = a.join('&');
    } else {
        var sPostParam = null;
    }
    oHttpRequest.open(sPostParam ? 'post' : 'get', sServerUrl, !bSync);//post 非异步
    oHttpRequest.setRequestHeader('If-Modified-Since', 'Thu, 01 Jan 1970 00:00:00 GMT');
    if (sPostParam) {
        oHttpRequest.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
        oHttpRequest.setRequestHeader('Content-Length', sPostParam.length);
    }
    oHttpRequest.send(sPostParam);
    if (bSync && typeof fnCallback == 'function') {
        fnCallback(oHttpRequest, vCallbackParam); //执行post方法返回的数
    }
}