c - 2 Functions in 1 main program(Visual Studio 2013) -

i wanna add 2 variables.in main program 2 functions. use visual studio 2013.there appears error c2660: 'function2': function not accept arguments 1

 #include "stdafx.h"  #include <stdio.h>  #include <stdlib.h>  double funktion1();  double funktion2();  int main()  { double c; {     c=funktion1();     funktion2(); //line 14 } return 0;  }  double funktion1()  { double a, b, c; printf("add 2 numbers!"); scanf_s("%lf%lf", &a, &b); c = + b; return c;  }  double funktion2(double c)  {  printf("\n result: %lf", c); //line 29     } 

thx help!

you use variable double c in statement printf. @ point, haven't assigned value c. warning, or error in case, telling you.

update:

when need return value of funktion1 in funktion2, must pass parameter, e.g.

int main() {     double c;     c = funktion1();     funktion2(c); }  /* ... */  void funktion2(double c) {     printf("\n result: %lf", c); //line 29 }