View Compilation Error

0_0_37307214_9682.cpp: In function 'int main()':
0_0_37307214_9682.cpp:7:50: error: 'scanf_s' was not declared in this scope
  while (scanf_s("%f %f %f %f", &x1, &y1, &x2, &y2) !=EOF)
                                                  ^