页面状态加载....

createMask();
function createMask()
{
    document.write("<div id='shield'  style='Z-INDEX:1000;filter:alpha(opacity=10);BACKGROUND-COLOR:#cccccc;LEFT:0;WIDTH:100%;POSITION:absolute;TOP:0;HEIGHT:100%'><br>&nbsp;&nbsp;&nbsp;<img src='images/loading.gif'>数据正在读入中,请稍等...</div>");
}


document.onreadystatechange = new Function("hiddenLay();");
function hiddenLay()
{
    if(document.readyState=="complete")
    {
         document.getElementById("shield").style.display="none";
    }
}
存成js,再head里引用就可以了