Logical error: Max always "0"?

Logical error: Max always "0"?

I try to write a program to finding Max number but the result appear "0".
This is my code:
public class Max_N_value {
public Max_N_value() {}
public static void main(String[] args) {
int i; int mynum[] = new int[50];
for( i=0;i<5;i++)
mynum[i]=Integer.parseInt(JOptionPane.showInputDialog(null,"
Value "));
if(mynum[i]>mynum[i+1]) {
JOptionPane.showMessageDialog(null,"Maximum value is "+mynum[i]);
else {
JOptionPane.showMessageDialog(null,"Maximum value is :
"+mynum[i+1]);
}
}
}