exponential

import javax.swing.JOptionPane;
public class exponential
{
public static void main(String[] args)
{
String inputx=JOptionPane.showInputDialog("Enter the number x of exp(x) ");
int x=Integer.parseInt(inputx);
String inputn=JOptionPane.showInputDialog("Enter a number n ");
int n=Integer.parseInt(inputn);
double i,j,k,b,a,sum=0;
for(i=0;i<=n;i++)
{
k=1;
for(j=i;j>0;j--)
k=k*j;
a=1;
for(b=i;b>0;b--)
a=a*x;
sum=sum+(a/k);
}
JOptionPane.showMessageDialog(null,"exp(x) = "+sum);
}
}