error LNK2019 unresolved external symbol

[jigar23]

I am trying to create a basic program with a user defined header file.I created the project in visual studio.

test1.cpp

#include <stdio.h>
#include "multiply.h"

int main()
{

    int y;
    y=multiply(5,10);
    printf("%d\n",y);
    printf("%s","jigar");
    getch();
    return 0;

}

multiply.h

int multiply(int a,int b);

multiply.c

#include "multiply.h"
int multiply(int a, int b)
{
    return a*b;
}

However while running the program test1.cpp I am getting the error as

Error 1 error LNK2019: unresolved external symbol "int __cdecl multiply(int,int)" (?multiply@@YAHHH@Z) referenced in function _main test1.obj

Some one please help me out ..

[zeroliken]

a C file always require a main function to execute as in the case of multiply.c

also if your making a C program use the extension .c for your main file .cpp is for c++ programs

[WaltP]

a C file always require a main function to execute as in the case of multiply.c

Take another look at test1.cpp. main() is right there!

After changing test.cpp to test.c, add multiply.c to the compile line.

[jigar23]

.cpp and .c doesnt make any difference if u r running a C code.
Thanx a lot for replying.
The issue is resolved. In visual studio, we have to add the the .c files which the .h file have calles to the source(in the solution explorer)