学步园

var iframe=document.getElementById('center');
					if(!iframe) return false;
					if (iframe.attachEvent){
					    iframe.attachEvent("onload", function(){
					    	
					    });
					    iframe.onreadystatechange=function(){
							if(this.readyState=="complete"){
								--------------操作---------------
							}
						};
					} else {
					    iframe.onload = function(){
					    	---------------操作----------------------
					    };
					}