<iframe id="frameContent" name="frameContent" onload="return IframeOnload('frameContent');" src="ชื่อ url iframe ของคุณ"          class="adm_iframe" frameborder="0" marginwidth="0" marginheight="0" scrolling="no" width="562px"></iframe>


<script type="text/javascript">

var isIE = (navigator.appName.indexOf("Microsoft")!=-1)? true:false;
function GetDocument(frameName)
{
    if( isIE )
    {
        return document.frames[frameName].document;
    }
    else
    {
        return document.getElementById(frameName).contentDocument;
    }
};
var tm_AutoHeightFrame = null;

function AutoHeightFrame(frameName)
{
    AutoHeightFrame1(frameName);
    if( tm_AutoHeightFrame == null )
    {
        tm_AutoHeightFrame = setInterval(function(){AutoHeightFrame1(frameName);}, 200);
    }           
};
function AutoHeightFrame1(frameName)
{
    var frm = document.getElementById(frameName);     
    if( frm == null ) return;
    var frameBody = GetDocument(frameName).body;
    if( frameBody == null ) return;
    var _height = frameBody.scrollHeight+10;
    if( _height < 360 ) {_height=360;} //you can change 410 to your own value, this is min height for iframe.
    frm.height = _height;
}     
function IframeOnload(frameName)
{
    AutoHeightFrame(frameName);
};

</script>