Able to stand without assistance

Was so excited on Sat. Kayden was able to stand without assistance for about 11s(max) when he was 10mths 4days old. I was assisting him in standing as usual as he wanted to see his daddy vacumming the room. He was very engrossed and i tried letting go of my hands and he remained standing. I was very excited and shouted for andy to come and take a look but the noise was too loud. When Andy came over, Kayden has already sat down. I tried again to let him stand without assistance but it failed. tried a couple of times later during the day. the longest he could stand without assistance was 11 sec as we counted '1000', '2000'. haiz... din managed to take his photo cos by the time we get our camera ready, he sat down liao.