Thread: Blocking Alpha characters

To start-- like many others-- I'm teaching myself C programming. It's been okay, but I have hit a speed bump--

I'm doing a currency conversion program and I have limited the user to just being able to select the number 1 to convert Pounds to US Dollars. I have my screen clear and reset if the user chooses a different number. However, if the user hits an alpha character, such as A, then the screen just goes black and sits there. How can I get the screen to reset or tell the user to try again if he/she hits an alpha character?

Thanks in advance for your help!

At the request, here is my code--- God, I hope I posted it correctly-- hate to make anybody mad when I'm the one looking for help!!

Code:

#include <stdio.h> 
     #include <conio.h> 

     #define GBP 1.8904; /* British Pound conversion rate    
          constant*/

     int main(void)
	
     {

	float usd;
	float newrate;
	int selection;

	do 
	{
	clrscr();
	

		
	
printf("This program will convert British Pounds to US Dollars\n");

printf("\n\nPlease Select The Number 1 And Press ENTER To Convert Pounds To Dollars:\n");

printf("[1] British Pound\n");
	
scanf ("%d", &selection);

printf("You entered %d\n", selection);
		
	}

	while (selection != 1);
	
	
printf("\n\nPlease enter the amount of money you want to convert to US Dollars\n\n\n");

scanf("%f", &usd);

newrate = usd * GBP; 

printf("\nThat amount in US Dollars is: $%.2f \n\n\n", newrate);


printf("\n\nThank you!  \nHave a great day! \nPress any key to exit\n");


	getch();

	return 0;
	}