text: //write include statements
  #include "dna.h"
  #include "iostream"
  #include "string"
  //write using statements
  using std::string;
  using std::endl;
  
  /*
  Write code that prompts user to enter 1 for Get GC Content, 
  or 2 for Get DNA Complement.  The program will prompt user for a 
  DNA string and call either get gc content or get dna complement
  function and display the result. Program runs as long as 
  user enters a y or Y.
  */
  int main() 
  {
  	char run = 'Y';
  
  	while (run == 'Y' || run == 'y')
  	{
  		int choice = 0;
  		string dna;
  
  		std::cout << "Enter 1 for Get GC Content." << endl;
  		std::cout << "Enter 2 for Get DNA Complement." << endl << endl;
  	
  		while(choice != 1 && choice != 2)
  		{
  			std::cin >> choice;
  		}
  
  		switch(choice)
  		{
  			case 1:
  			{
  				std::cout << "Enter DNA string: ";
  				std::cin >> dna;
  
  				std::cout << "GC Content: " << get_gc_content(dna) << endl;
  
  				break;
  			}
  			case 2:
  			{
  				std::cout << "Enter DNA string: ";
  				std::cin >> dna;
  
  				std::cout << "DNA Complement: " << get_dna_complement(dna) << endl;
  			}
  		}
  
  		do
  		{
  			std::cout << "Run again? (y/n): ";
  			std::cin >> run;
  		} while (run != 'Y' && run != 'y' && run != 'N' && run != 'n');
  		
  		std::cout << endl;
  	}
  
  	return 0;
  }