Q: How to change the location of a grandchild iframe? Please consider the following example.
TopPage (siteA.com)
|- iFrameB (siteB.com)

 |- iFrameC (siteC.com)

Top page has iframeB operating on  origin. Within iFrameB, there is iFrameC of which inner document location is http://siteC.com
Is there any way for TopPage(siteA.com) to change the location of iFrameC from http://siteC.com to another page? (Please be aware that TopPage and iFrameB operate on different origins)
I am desperately looking for answers.
