In IE8, the javascript operation frame returns undefined.

A hidden frame is defined on the page to submit applications such as generating reports. There was no problem with the previous use. Today, I suddenly did not use it. After debugging, the returned value of parent. frames ("listFrm") is undefined.

Later, the frames parameter was changed to a non-hidden frame, and the problem was solved.

The day before yesterday, I had an Internet Explorer 8 installation. I think this is the only possible problem.

PS: in actual testing, several versions of IE can install a software called IETester, which is not bad. The reason is unclear. However, I used to do something similar to you before. I didn't "hide" the frame, but set its width and height and its border to 0. Actually, it still exists, it's just "not visible. In fact, I don't know what you are doing, but why don't I try Ajax to submit it?