onerror in html code example
Example: oneerror javascript image
<img src="imagenotfound.gif" alt="Image not found" onerror="this.onerror=null;this.src='imagefound.gif';" />
<img src="imagenotfound.gif" alt="Image not found" onerror="this.onerror=null;this.src='imagefound.gif';" />