Waseem, again thank you for your help. Now, this is what I'm trying to do. (I'm adding a couple of screenshots for further detail)
First image: As you can see, I have a unordered list with an id of "filter" that *filters* the items of the also unordered list with an id of portafolio. The filtering works by adding a class of "current" to the items that are visible (and match the category you're clicking, eg web, print, etc) and a hidden class (witha a display:none) to the ones that are hidden. The div with an class of portfolioclip is the container of the portfolio items and it initially displays ONLY the first three items, regardless if the number of items made visible by the filtering script is higher. The .portfolioclip has a height of 225px and overflow:hidden. So when one clicks in the plus button (#portfolio-morelink) I want the container's height to grow automatically to show all the visible items, as you can see in the next image. I've sort of accomplished this toggling the class of the container with jQuery to .portfoliofull (height:100%) and a 2000 ms duration so it slides smoothly when it grows. $s('.portfolioclip').toggleClass('portfoliofull', 2000); return false; }); The problem, as I stated in the first post, is that Internet Explorer doesn't pick the duration value and it expands/contracts the div very harshly, no smooth animation. I've read I can do this with toggling the initial height (232px) with the final height (auto) but I don't understand how to state the initial height is different than 0. So it goes from 232px to 0 which is not what I want. Also I tried with animating the height without the toggling and it works fine except it only works once cause since there is no toggling, the div doesn't return to its previous state. I hope I've explained myself. If not, please tell me what more info do you need and I will answer. Again, thank you very much. PD: The link, once more, is http://invitro.vegasoftweb.com/es/