C :: Searching Word Using Strcmp

I'm trying to write function that finds wheter the searched word exists or not. The compiler gives warning. Where is my wrong ?

|21|warning: passing argument 1 of 'strcmp' makes pointer from integer without a cast [enabled by default]|

Code:

#include <stdio.h>
#include <string.h>
int main ()
{
int result;
char arr[]="sakir emmim evde mi evde mi dedik lan";
int size=sizeof(arr)/sizeof(char);
char key[20];
scanf("%s", &key);

[Code]...