As I said before, if I need to ensure images that my js uses have completed downloading, I will put the js in the onload. it will be executed as soon as the parser reads it, as long as it doesn't reference an element not yet created As one of the core technologies of the web alongside HTML and CSS, JavaScript is used to make webpages interactive and to build web apps. In my sense,I will tell you should learn Javascript before PHP. just insert a