Thread: where I'm wrong?

i'm trying to develop a code to add two matrixes and then store result in another matrix but i use to get arrayoutofbounds expection every time i try to run it. please let me know where I'm going wrong?
have a look at my code

public class MatrixAdd {
	static int[][] test1a = {{1,2,3,4},{5,6,7,8},{9,10,11,12}};
	static int[][] test1b = {{1,2,3,4},{5,6,7,8},{9,10,11,12}};
	static int[][] test2a = {{1,2,3,4,5,6,7,8},{9,10,11,12,13,14,15,16}};
	static int[][] test2b = {{1,2,3,4,3,2,1,0},{5,6,7,8,9,10,11,12}};
 
	static int[][] testcaseA = test2a;
	static int[][] testcaseB = test2b;
 
	public static void main(String args[]){
		MatrixAdd inst = new MatrixAdd();
		int[][] v = inst.add(testcaseA,testcaseB);
		System.out.println(v);
	}
 
	// Write your code in the function below
	public int[][] add(int[][] m1,int[][] m2){
 
	int result[][];	
 
	int lb=m2.length;
	result = new int[lb][lb];
	for(int i = 0; i <lb; i++) 
  	for(int j = 0; j <m2[i].length; j++) 
  	result[i][j]=m1[i][j]+m2[i][j]; Eror is here.
	return  result;
	}
}

i'm not getting it where i'm wrong??