Select elements in the iframe from the parent page:
$( '#btnCancel',$('#PopFrame')[0].contentWindow.document)
Select elements in the parent page from the iframe page:
$("#PopContainer",parent.document)
The following is the solution from other netizens:
It had to be implemented by combining the DOM method and the jquery method
1. Select all the radio buttons in the IFRAME in the parent window
$(window.frames["iframe1"].document).find("input[@type='radio']").attr("checked","true");
2. In IFRAME Select all radio buttons in the parent window
$(window.parent.document).find("input[@type='radio']").attr("checked","true");
iframe:
Test passed in IE7