Thread: How to make a simple menu

I want to make a menu whicch allows the user to select either male or female. if none of those two are selected, the program should print "invalid option". If the user chooses among the two... the program continues. Please help me.

Code:

   
      printf("\n Select the sex (gender) of Subscriber: \n");
      printf("\n1. Male");
      printf("\n2. Female");
      scanf("%s",&s1);

 	char s;

  	FILE *sfPtr;
 	customer sex = {"",""}; 	/* Here is the error... what to put there? */
 	char choice;

 	if ((sfPtr = fopen("Subscriber.txt", "w")) == NULL)
 		printf("File could not be opened.\n");
 	else
 	{
 		for(s=1;s<=1;s++)
   		fwrite (&sex, sizeof(customer), 1, sfPtr);

 	}
 	
 	fclose (sfPtr);
 	
    printf("\nPlease enter m or f, To exit enter n: ");
    scanf("%s", &choice);
        
    while (choice != 'n')
        {
 	
 	     if ((sfPtr = fopen ("Parent.txt", "rb+"))== NULL) {
   	        printf("Unable to open file!!\n");
         }
         else {
        
              switch (choice)
      	      {
               case 'M':
 	           case 'm':
         		    Registration (sfPtr);
         		    fclose (sfPtr);
                    break;
               case 'F':
               case 'f':
            	    Find (sfPtr);
            	    fclose (sfPtr);
  	                break;
               default:
                       printf("\nIncorrect choice, Please select a valid option: ");
  	                   break;
               }
            }
            printf("\nPlease enter m or f, To exit enter n: ");
            scanf("%s", &choice);
        }
      
 	//Subscriber (sfPtr);
 	//Find (sfPtr);
 	fclose (sfPtr);

Why would you put anything there? And is customer a valid type name? (It doesn't appear to be.)

Presumably you already have an instance of the customer struct running around? You've already gotten name, and address, and ID, etc, right? So just add the response to the .sex field of that struct and you're done. You don't make a brand new customer just for this.