Tax calculator with menu

This is my project and this is what I have so far, it wa able to compile but there is a linker error.  
Project: Tax calculator that multiply the tax rate by the purchase amount 100.00.  Then I have to modify the
simple tax calculator by adding a menu.  Itried to combine the two in one project and was able to compile, but have a linker error:

This is what I have
#include<stdio.h>
/*DelMar = 7.25 %/
/*Encinitas = 7.50%/
/*La Jolla = 7.75%/

printf("Tax Calculator\n");
//prompt the user to enter amounts
printf("\nSelect (a) calculate tax\n");
printf("\nSelect (0) to exit\n");
scanf("%c", &userSelect);
tax=price*0.0725;// Del Mar tax calculation
tax=price*0.0750;//Encinitas tax calculation
tax=price*0.0775;//La Jolla tax calculation
switch (task){
{
 case 1: DelMar:
      {      
      rate = 7.25;
      break;
      }
 case Encinitas:{
      rate = 7.5;
      break;
     
 case La Jolla:
      rate = 7.75;
      break;
     
}
int main()
{
     int task;
     char c;
     float myAmount;
     do
     {