Potty training

Hello I'm new to the blogging so I will just tell a little about me.... I have 4 kids Jess 17, linzey 4 , Nikolas 3 and Alec 19 months..... I stay at home cuz day care for 3 is outrageous... I have just witnessed what its like to potty train a boy, its be a nightmare. My son is now peeing every where but the potty... Walls, floor, bathtub and of course outside and in anything round... If there is any advice out there who have had similar problems HELP....