JS跳出框架返回上一页

<a class="link" href="javascript:;" target="_top" onclick="goback()">返回上一页</a>

<script type="text/javascript">
function goback(){
if(window.history.length > 1){
    javascript:history.go(-1);
    window.frames[‘workspace‘].document.getElementById(‘workspace‘).location.reload();  
}else{  
    alert("没有了");  
     }  
}
</script>

 <iframe frameborder="0"width="100%" id="workspace" name="workspace"></iframe>