function position(elem,l,t){
    var isIE6 = !-[1,] && !window.XMLHttpRequest;
    if(isIE6){
        var style = elem.style,
        dom  = '(document.documentElement)',
        left = l - document.documentElement.scrollLeft,
        top  = t - document.documentElement.scrollTop;
        style.position = 'absolute';
        style.removeExpression('left');
        style.removeExpression('top');
        style.setExpression('left', 'eval(' + dom + '.scrollLeft + ' + left + ') + "px"');
        style.setExpression('top', 'eval(' + dom + '.scrollTop + ' + top + ') + "px"');
    }else{
        elem.style.position = 'fixed';
    }
}     
function scscms_alert(msg,sign,ok,can){
    var c_=false;//是否已经关闭窗口，解决自动关闭与手动关闭冲突
    sign=sign||"";
    var s="";
    $("body").append(s);
    $("#scs_alert").css("margin-top",-($("#scs_alert").height()/2)+"px"); //使其垂直居中
    $("#scs_alert").focus(); //获取焦点，以防回车后无法触发函数
    position(document.getElementById('mask_layer'),0,0);
    position(document.getElementById('scs_alert'),$(window).width()/2,$(window).height()/2);
    if (typeof can == "number"){
    //定时关闭提示
        setTimeout(function(){
            close_info();
        },can*1000);
    }
    function close_info(){
    //关闭提示窗口
        if(!c_){
        $("#mask_layer").fadeOut("fast",function(){
            $("#scs_alert").remove();
            $(this).remove();
        });
        c_=true;
        }
    }
    $("#alert_ok").click(function(){
        close_info();
        if(typeof(ok)=="function")ok();
    });
    $("#confirm_ok").click(function(){
        close_info();
        if(typeof(ok)=="function")ok();
    });
    $("#confirm_cancel").click(function(){
        close_info();
        if(typeof(can)=="function")can();
    });
    function modal_key(e){
        e = e||event;
        close_info();
        var code = e.which||event.keyCode;
        if (code == 13 || code == 32){if(typeof(ok)=="function")ok()}
        if (code == 27){if(typeof(can)=="function")can()}      
    }
    //绑定回车与ESC键
    if (document.attachEvent)
        document.attachEvent("onkeydown", modal_key);
    else
        document.addEventListener("keydown", modal_key, true);
}
//====================================以下为测试函数=======================================//
function test1(){
    scscms_alert("默认提示信息");
}
function test2(){
    scscms_alert("成功提示信息","ok");
}
function test3(){
    scscms_alert("成功提示后回调函数","ok",function(){alert("回调成功！")});
}
function test4(){
    scscms_alert("失败提示信息","error");
}
function test5(){
    scscms_alert("失败提示信息","error",function(){alert("哦！no!")});
}
function test6(){
    scscms_alert("警告提示信息","warn");
}
function test7(){
    scscms_alert("警告提示信息","warn",function(){alert("哦！警告!")});
}
function test8(){
    scscms_alert("您喜欢此信息提示吗？","confirm",function(){
        scscms_alert("您选择了喜欢，谢谢！","ok");
    },function(){
        scscms_alert("您选择了不喜欢，汗！","error");
    });
}
function test9(){
    scscms_alert("本信息3秒后自动关闭","ok","",3);
}
function test10(){
    scscms_alert("询问信息定时关闭提示信息,3秒后自动关闭，无取消时回调函数.不推荐使用。","confirm",function(){alert("确定回调用！")},3);
}