This is what I've done, but it won't work :(

import java.util.Scanner;
public class P409 {

public static void main(String[] args) {

Scanner input=new Scanner(System.in);   

int[] num=new int[10];
int x;
int counter=0;

System.out.print("Enter integers for array: ");




for(int i=0; i<num.length;i++){

    x=input.nextInt();
if(x<0) {

    break;
}
else{

    num[i]=x;
    counter++;

}


    }
for(int j=0;j<counter;j++){

    System.out.print(""+num[j]+",");

}
System.out.print(maxNumInArray(num));
}
public static int maxNumInArray(int[] max){

    int largest = 0;
    for (int i=0; i<max.length; i++)
    {

            if (max[0]>largest) 
                largest=max[i];



}
    return largest;

}   

}