My first joke

Johnny : "Miss may I please go to the toilet?"
Teacher : "First say the alphabet please."
Johnny : "A,b,c,d,e,f,g,h,i,j,k,l,m,n,o,q,r,s,t,u,v,w,x,y and z."
Teacher : "Where's the"p" Johnny?"
Johnny : "Trickling down my leg Miss!"