用DIV模拟TEXTAREA【QQ空间说说对话框】

<script language="javascript">
function show(){
if(document.getElementById("mydiv").innerHTML=="我也说一句"){
document.getElementById("mydiv").innerHTML="";
document.getElementById("mydiv").focus();
}
}

function hide(){
if(!document.getElementById("mydiv").innerHTML){
document.getElementById("mydiv").innerHTML="我也说一句";
}
}
</script>

<div tabindex="0" contenteditable="true" id="mydiv" hidefocus="true" onfocus='show();' onblur='hide();' style="border:1px solid #ccc;width:200px;height:200px;">我也说一句</div>