Strict IE and Firefox tolerance

Today, I encountered a very strange browser compatibility problem. I used js to generate a pop-up window. The shell of the pop-up layer is fixed HTML. Code The content is called asynchronously by the backend Using ajax. The content is basically such an HTML section. I will extract an incorrect section. < A Href = "Javascript: void (0 );" Onckick = "Pop ('sp3b ')" > General lobby < A > < BR />
< A Href = "Javascript: void (0 );" Onckick = "Pop ('sp3b ')" > Special lobby < A > < BR />

the code is simple enough. If you look at it carefully, you will find that my HTML is a little problematic-the mark is not closed. It is also strange to me that I did not find this small error after looking for a long time. It took me a whole morning to find this error. When I found it, I really wanted to yell. In Firefox, this code is okay and can be displayed normally, but it won't work in IE. It has already encountered many such errors, write it down to prevent another colleague from making a mistake