knn in R: 'train' and 'class' have different lengths -

i trying build knn model in r, have cleaned data , got rid off outlier , normalized numeri values. however, when try run comes : "error in knn(train = x_train, test = x_test, cl = x_train_target, k = 57) : 'train' , 'class' have different lengths".

any or comments appreciated. thank you!

#eliminating na's nrow(d0[!complete.cases(d0),]) #which gave me 35 rows na's d0 <- na.omit(d0) nrow(d0[!complete.cases(d0),])  #dealing outliiers d0 <- subset(d0, night.mins > 0)  d0 <-subset(d0, night.mins <350)   #normalization  churn <- d0$churn. d0$area.code <- null #excluding  d0$state     <- null d0$churn.    <- null d0$phone     <- null d0$vmail.plan <-null d0$int.l.plan <- null x_1 <- d0   normalizer<- function(x) { return( (x-min(x))/(max(x)-min(x)) ) }  x_1 <- as.data.frame(lapply(x[,c(1:15)], normalizer))  x_1$churn. <- churn  set.seed(9850)#mixer y   <- runif(nrow(x)) x_1 <- x_1[order(y),]#mixed of data trainrows <- sample (nrow(x_1),0.7*nrow(x_1))#training data x_train   <- x_1[trainrows,] x_test   <- x_1[-trainrows,]# test data x_train_target <- x_1[trainrows,x_1$churn.] x_test_target <- x_1[-trainrows,x_1$churn.]   require(class) m1 <- knn( train= x_train, test= x_test, cl= x_train_target, k=57)}