关于有ajax 请求的iframe自适应高度问题

1 document.onreadystatechange=function() {  
2           if(document.readyState=="complete"){
3            window.parent.document.getElementById("iframeID").height=document.body.scrollHeight;
4               }  
5     }

    function getheightouat(){
                window.parent.document.getElementById("iframeID").height=document.body.scrollHeight;
    }
    $(document).ajaxStart(function(){})
    .ajaxComplete(function(){
        getheightouat();
    }).ajaxStop(function(){});