JS/CSS style.transition

[SigmaTec]

Hi all,

in this JS, I manage CSS attributes of an image, but "transition" doesn't work : is there any reason ?

Thank's in advance for your help.

Code:

$(function(){
  if (typeof grp != 'undefined') {
    grp.listen('0/0/2', function(object, state) {
      var value = object.value;
      if (value == 10) {
    var elem = document.getElementsByClassName('testVR');
    elem[0].style.transition = 'height 2s linear 1s';
    elem[0].style.height     = '100px';
    elem[0].style.overflow   = 'hidden';       
        }
      },true);
  }
});