I'm potty training my two and half year old son. He will sit on the toilet sometimes without a fight. Sometimes he pees, if he does he receives praise and a "treat". Once I get him off the toilet within five minutes he pees his diaper even though he had just gone on the toilet. My concern is he may have a weak bladder. I has putting him on the toilet every hour then every half hour but before the half hour is up he has already pee. Please help.