`strcmp' undeclared (first use this function)

[cralx2k]

#include <stdio.h>int main (){char password[20];char userPassword[20];FILE *mFile;mFile = fopen("password.txt", "r");         if (mFile == NULL){            printf ("File not found!");             return 1;         }else  {                printf ("File found!\n");                int i = 0;                      while (!feof(mFile)) {                      fscanf (mFile, "%c", &password[i]);                      i++;                }                                     password [--i] = '\0'; 
                       printf ("\nPlease enter a password:");                        scanf("%s", userPassword);
                      [color=Red] if(!strcmp (userPassword, password))[/color]                               printf("The password is correct!");                       else                                printf("The password is wrong!");
                }                                      return 0;}

Porque esta com esse erro quando compilo....

[Matheus Maldi]

adicione

#include <string.h>

[cralx2k]

Valeu Matheus