求教一道简单的题目

帮忙改正一下，谢了！！！！！！！！！！！！！！！！！！！

//Fig 2.26:MaxFive.java
//求输入五个数中的最大数与最小数

import javax.swing.JOptionPane;

public class MaxFive{
public static void main(String args[])
{
String firstNumber;
String secondNumber;
String thirdNumber;
String forthNumber;
String fifthNumber;

int number1=0;
int number2=0;
int number3=0;
int number4=0;
int number5=0;
int Max;
int Min;

firstNumber=JOptionPane.showInputDialog("Enter first integer:");
number1=Integer.parseInt(firstNumber);

secondNumber=JOptionPane.showInputDialog("Enter second integer:");
number2=Integer.parseInt(secondNumber);

thirdNumber=JOptionPane.showInputDialog("Enter third integer:");
number3=Integer.parseInt(thirdNumber);

forthNumber=JOptionPane.showInputDialog("Enter forth integer:");
number4=Integer.parseInt(forthNumber);

fifthNumber=JOptionPane.showInputDialog("Enter fifth integer:");
number5=Integer.parseInt(fifthNumber);

Max=Ma(number1,number2,number3,number4,number5);/*求五个数中的最大数*/
Min=Mi(number1,number2,number3,number4,number5);/*求五个数中的最小数*/

JOptionPane.showMessageDialog(null,"The max of five integer is "+Max);
JOptionPane.showMessageDialog(null,"The min of five integer is "+Min);
System.exit(0);
}


public int Ma(int number1,int number2,int number3,int number4,int number5)
{
int temp1;
int temp2;
int temp3;
int temp4;

temp1=Math.max(number1,number2);
temp2=Math.max(number3,number4);
temp3=Math.max(temp1,temp2);
temp4=Math.max(temp3,number5);

return temp4;
}

public int Mi(int number1,int number2,int number3,int number4,int number5)
{
int temp1;
int temp2;
int temp3;
　　　　　　　　　int temp4;

temp1=Math.min(number1,number2);
temp2=Math.min(number3,number4);
temp3=Math.min(temp1,temp2);
temp4=Math.min(temp3,number5);

return temp4;
}

}

提示错误如下：
E:\JCreator Pro\MyProjects\wELXOME\w\Welcome1.java\MaxFive.java:38: non-static method Ma(int,int,int,int,int) cannot be referenced from a static context
Max=Ma(number1,number2,number3,number4,number5);
^
E:\JCreator Pro\MyProjects\wELXOME\w\Welcome1.java\MaxFive.java:39: non-static method Mi(int,int,int,int,int) cannot be referenced from a static context
Min=Mi(number1,number2,number3,number4,number5);
^
2 errors

Process completed.