My iphone4 doesn't show up in Itunes

When i plug my iphone4 into my laptop with the USB cable, it normally automatically comes up in itunes, however it's not doing that anymore, nothing is coming up not even an icon all that pops up is my PC documents saying to sync pictures,I have tried everything that i have seen on the internet to fix this problem but nothing is working, i have deleted and re-installed itunes and i have resarted my laptop. Please can you help me ASAP thank you very much. Alishaa(: