Use php to generate snippet code of html or javascript [closed]

It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, visit the help center. Closed 11 years ago.

Simply want to use php to generate snippet in javascript or html that can access images from another server if they meets criteria as they are registered and active.

Example. if i have some users that have avatars if they want to embed their avatar on their own website they use snippet code generated by php app(they include snippet code in website page to show avatar that is 开发者_JS百科on another server where my php app lie ). Snippet only show their image by applying some conditions e.g where the request came from etc

---

if ( //conditions are met ) {
    echo '<img src="path_to_image" />';
}