document.onkeypress = function(e){
if(e.keyCode == 116){
e.preventDefault(); //组织默认刷新
var iframeSrc = iframe.src;
iframe.src = iframeSrc;
}
}iframe页面里再写如下：
var iframeSrc = parent.iframe.src;
document.onkeypress = function(e){
e.preventDefault();
parent.frame.src = iframeSrc;
}