Deallocating Memory allocated to a pointer to a pointer

Hello. Please help me out with the following code...

Code:

`class MATRIX`

{

private:

float **x;

int m,n;

public:

MATRIX();

MATRIX(int, int);

void getdata();

void showdata();

~MATRIX();

};

MATRIX::MATRIX()

{

m=1; n=1; x=new float*[1]; x[0]=new float[1]; x[0][0]=0;

}

MATRIX::MATRIX(int a, int b)

{

int ctr,row,col;

m=a; n=b;

x=new float*[m];

for(ctr=0; ctr<m; ++ctr)

x[ctr]=new float[n];

for(row=0; row<m; ++row)

{

for(col=0; col<n; ++col)

x[row][col]=0;

}

}

MATRIX::~MATRIX()

{

//what do I type here?

}

I am unable to figure out what code I should use in the destructor to deallocate the memory allocated to the pointer to a pointer x.

Please help out.