HTML使用要点

<script>
    $(function(){
        $("#button1").click(function(){
            $.get("/template/", function(ret){
            });
        });
    });
</script>
......
<button id="button1">button1</button><br/>

<script>
    function sure(){
        alert("Are you sure？");
    }
</script>
......
<button onclick="sure();">想好了</button>

if($(".show-picture").attr("src")!=undefined)
......
//<img id="show-picture" src=""  >
    判断是否有该element .
if(document.getElementById("active_box")!=null)
{
......
}

var filePath = $("#img").val();
var arr=filePath.split('\\');
var fileName = arr[arr.length-1];

//设置标签的左边距
<div style="margin-left: 30px;">
//字体加粗
<b>加粗</b>

document.getElementById(id);
document.getElementsByTagName(tagName);
document.getElementById(id).getElementsByClassName(className);