兼容ie ff iframe高度自适应

  formeName为你的iframe的id  layer1 为显示页面div的id

  红色部分是用来区别ie和ff的

<script type="text/javascript">
                           function changeCHK(formName){  

                            document.getElementById(formName).style.height =140; (formName).contentWindow.document.getElementById("Layer1");
                             if(div1!=null){
                              var layer1=document.getElementById(formName).contentWindow.document.getElementById("Layer1");
                                                          if(document.all){
                               document.getElementById(formName).style.height =  Math.max(layer1.scrollHeight+40,140);
                               }
                               else{
                               document.getElementById(formName).style.height =  Math.max(layer1.scrollHeight,140);
                               }
                             }else{
                              document.getElementById(formName).style.height = (document.getElementById(formName).contentWindow.document.body.clientHeight)+"px";
                             }
                           }
                          </script>