上传问题

<script type="text/javascript">
function c(obj)
{
 var imgsrc=this.getFullPath(obj); //imgsrc他的路径是绝对的本地路径，路径看过是正确的！
 document.getElementById("Imag").setAttribute("src","'"+imgsrc+"'");}
</script>
<body>
<s:form action="headPortrait_headAdd_" name="form" theme="simple" enctype="multipart/form-data">
<h3 >当前头像</h3>
<img id="picc" src="headImage/yuans.jpg" width="120" height="120" />
<br/>
<h3 >更换头像</h3>
<s:file name="ppa" ContentEditable="false" onChange="c(this)"/>
<s:submit value="上传图片" /><br>
</s:form>
</body>