Exemple de code de la propriété JS / CSS letterSpacing.

<script type="text/javascript"> 
function setproperty(Objet,value,initvalue){ 
	if(Objet.style.letterSpacing == value){ 
		Objet.style.letterSpacing = initvalue; 
	}else{ 
		Objet.style.letterSpacing =value; 
	} 
} 
</script> 
ObjetJavascript.style.letterSpacing = "normal"; 
<div style="cursor:pointer; cursor:hand; letter-spacing:15px" onclick="setproperty(this,'normal','15px')">Cliquez moi. letterSpacing</div> 
ObjetJavascript.style.letterSpacing = "15px"; 
<div style="cursor:pointer; cursor:hand" onclick="setproperty(this,'15px','normal')">Cliquez moi. letterSpacing</div>