can someone please tell me how functions work??

[HotaLIsa]

i am teaching myself c++ and i thought that when i pass an argument to a function it supposed to use it. but his one says "salary was not declared in this scope" what????

  #include <iostream>
 
using namespace std;


void qualify(){
	cout << "congratulations you qualify!! our card comes with a 12% annual interes fee." << endl;
}
 
 void noQualify();		// function prototype
 
int main()
{
 double salary;
 int years;
 
 
 cout << "This program will determine if you qualify\n";
 cout << "for out cridit card.\n";
 cout << "what is your annual salary? ";
 cin >> salary;
 cout << "How many years have you worked at your ";
 cout << "current job? ";
 cin >> years;
 if (salary  >= 17000.0 && years >= 2)
 	qualify();
  else
  	noQualify(salary);
  return 0;
}
 
 void noQualify(){
 	if (salary < 17000.0)
 		cout << "your salary isnt enough to meet our minimum requierments." << endl;
 	else
 		cout << "you dont have the experiance in your work area to meet our minimum requierments." << endl;
 }

[HotaLIsa]

nvm ignore me, i figured it out