About createWrapper in effects.core.js

About createWrapper in effects.core.js


Hello everybody
I'm sorry to duplicate this post from jquery-dev but I really need an
answer for it.
My question is about those two lines of code :
var top = parseInt(el.css('top'), 10); if(isNaN(top)) top = 'auto';
var left = parseInt(el.css('left'), 10); if(isNaN(left)) left =
'auto';
In which we parseInt the values of el.css("top/left") and then we
check if the value was auto (for IE/Opera).
I'm wondering why we need to parseInt those values.
Your help will be greatly appreciated : )