alt attribute in an image tag code example

Example: html img alt

<!-- The required alt attribute specifies an alternate text for an image, 
if the image cannot be displayed (screen reader...). -->
<img src="img_girl.jpg" alt="Girl in a jacket" width="500" height="600">

<img src="img_girl.jpg" alt="Girl in a jacket" 
     longdesc="img_girl-longdesc.html">  <!-- long description -->