private void Validate(int row, int col)
{
if ((row >= Rows) || (row < 0))
{
throw new MatrixError("The row:" + row + " is out of range:"
+ Rows);
}
if ((col >= Cols) || (col < 0))
{
throw new MatrixError("The col:" + col + " is out of range:"
+ Cols);
}
}