为什么这个矩阵乘法不能运行?
源代码如下   : 
 improt   java.io.*; 
 public   class   MultiMatrix   { 
   int[][]   multiplyMatrix; 
   public   static   void   main(String   args[]){ 
   int[][]   a={{1,0,3,-1},{2,1,0,2}}; 
   int[][]   b={{4,1,0},{-1,1,3},{2,0,1},{1,3,4}}; 
   MultiMatrix   mm=new   MultiMatrix(); 
             mm.mMatrix(a,b); 
   mm.display();     
   } 
   public   void   mMatrix(int[][]   a,int[][]   b){ 
   multiplyMatrix=new   int[a.length][b[0].length]; 
   for   (int   i   =   0;   i <a.length;   i++)   {//rows   of   a 
   for   (int   j   =   0;   j <b[0].length;   j++)   {//columns   of   b 
   for   (int   k   =   0;   k <a[0].length;   k++)   {//columns   of   a   =   rows   of   b 
   multiplyMatrix[i][j]=multiplyMatrix[i][j]+a[i][k]*b[k][j]; 
   } 
   } 
   } 
   } 
   public   void   display(){ 
   for   (int   i   =   0;   i <multiplyMatrix.length;   i++)   { 
   for   (int   j   =   0;   j <multiplyMatrix[0].length;   j++)   { 
   System.out.print   (multiplyMatrix[i][j]+ "    ");     
   } 
   System.out.println   ( " "); 
   } 
   } 
   }              
 出错信息是Exception   in   thread    "main() "   java.lang.NoClassDefFoundEerror:MultiMatrix.java 
 请教高手帮我解决下,急用?
------解决方案--------------------Are you trying to execute your program like this? 
     java MultiMatrix.java   
 This is wrong. Use the main class name as the argument of java command. 
     java MultiMatrix 
------解决方案--------------------同 z_lping(Schemer) 能编译,能运行 
 你用什么环境的?   
 ----------------------------------- 
 http://ma3310.vicp.net
------解决方案--------------------把类名MultiMatrix改成MultiMatrixy就可以了,试试看