exemplo:
CODE
<html> <head> <script type="text/javascript"> function updateFrameCheck(childName, status) { var x = document.getElementById("frameThing"); var y = x.contentDocument.getElementById("formIdFromIframe"); y.elements[childName].checked = status; } </script> </head> <body> <iframe src="otherpage.htm" id="frameThing"></iframe> <input type="checkbox" onclick="updateFrameCheck(this.name, this.checked)" name="childName" /> </body> </html>
veja tambem
http://pt.w3support.net/index.php?db=so&id=580941abraço