Write image as external style using CSS

[eriktherandom]

I have the html code as below:\[code\]<img src="http://stackoverflow.com/questions/images/ffp.jpg" alt="Adiscos membre de la F&eacute;d&eacute;ration de la Formation Professionnelle" name="Adiscos membre de la F&eacute;d&eacute;ration de la Formation Professionnelle" width="100" id="Adiscos membre de la F&eacute;d&eacute;ration de la Formation Professionnelle" />\[/code\]I wan to write it as external css How should do with this? Anyone help me please, thanks.