When writing html5, debugging found that the script php and other web pages js, css, etc. were invalid_html5 tutorial skills

Recently, when writing HTML5, I simply debugged it and used it in conjunction with PHP. I found that in many cases js, css, etc. would fail and the page would display abnormally, which was not the case before when it was not HTML5. After consulting all kinds of information, I found after debugging: The web page is still cached when jumping. It is necessary to point out the relationship between the original web page and the web page after the jump. Therefore, in the code:

1. Use the form to jump To transfer, you need to add target in the form element, such as: