即使使用'load'，div也不会重新加载更改的内容

I have been working on this for some time now. I have a php file that has a div which reads a directory and loads the files in the directory into a dropdown. When the user selects from the file the file gets selected and teh operation is performed. However, the file name does not disappear from the dropdown until the page is refreshed. I have tried '.load' and it doesn't work. As in, the content of the div does not get updated.I have been working on this for some time now.