if my phone gets wet, is it ruined ?

Your phone won't be ruined forever if it gets wet, but you need to act pretty quickly to save it. The first step, is to whip out the battery, SIM card and SD card to make sure they don't suffer too much water damage. Dry your phone by burying it in uncooked rice or silica gel packets to absorb all the moisture. If you've done this, then there is a chance your phone might just survive.