Write a C Program that appends the one string to another string

Write a C Program that appends the one string to another string

1:  #include<stdio.h>  
2:  #include<conio.h>  
3:  #include<string.h>  
4:  int main()  
5:  {  
6:        char str[100],app[20];  
7:        clrscr();  
8:        printf("Enter the string :");  
9:        gets(str);  
10:        printf("Enter the srting that you want to append : ");  
11:        gets(app);  
12:        printf("The string is : %s\n",str);  
13:        printf("The string you want to append is : %s\n",app);  
14:        printf("The string after append is : %s\n",strcat(str,app));  
15:        getch();  
16:        return 0;  
17:  }