<body onLoad="setInterval(trim,100)">
<p id="exp"></p >
<script>
var exp=document.getElementById("exp");
var str="我笑便面如春花，定是能感动人的，任他是谁！";
y=1;
function trim(){
var trimstr=str.substring(0,y);
exp.innerHTML=trimstr;
if(y<str.length) y++;
else clearInterval(setInterval(trim,100));
}
</script>
</body>
</html>
