want to have alert() send current fontSize value of a specified element
 

my alerts are blank.

not sure what i am missing.

1.to use that method you must have had that style inside the tag (or pre set up on-the-fly by a javascript function), not as an external CSS code.

<div id="body" style="font-size:20px">text</div>

2. If you have an embedded or external code, the syntax is otherwise

for IE
document.getElementById("body").currentStyle.fontSize
for Mozilla
document.defaultView.getComputedStyle(document.getElementById("body"),'').getPropertyValue("font-size")

ah, okay. thanks.