btn in php page don't redirect to another page

I have php page calling another php page by ajax the second page contain form have a button when i click the btn it should go to a third page but action didn't work the page stay as it is and don't do any thing . by the way the code to examine action is on the top of the first page(mpther page) I tried to copy it to the top of the second page but also it didn't work . any help?