Thread: goto command

I am having trouble with the goto command in the code below. The program should make two validation. First is if store selection is correct and second is if purcahse amount is numeric. If either is invalid the program should jump to ask the user if they want to try again. I have the first one working but if the user inputs an invalid sale amount(ie an alpha caracter), the program jumps to the terminate program line. Any suggestions?

thanks

Code:

#include <stdio.h>

main()
{

// variables
    int iResponse;
    int validate; 
    float purchaseAmount= 0.0;
    float delMarTaxRate=.0725;
    float encinitasTaxRate=.075;
    float laJollaTaxRate=.0775;
    float tax = 0.0;
    char option = 'Y';
// Menu Selection

	start:
    printf("\n\t\tStore Location\n");
    printf("\n\t1\tDel Mar\n");
    printf("\t2\tEncinitas\n");
    printf("\t3\tLa Jolla\n");
    printf("\nPlease select a location: ");
    scanf("%d", &iResponse);
    

switch (iResponse) 
	{

    	case 1:
        	printf("\nYou selected Del Mar\n\n");
        	break;
    	case 2:
        	printf("You selected Encinitas\n\n");
        	break;
    	case 3:
        	printf("You selected La Jolla\n\n");
        	break;
    	default:
        	printf("Invalid selection\n\n");
        	goto skip_point;
        
	} //end switch

// Input sale amount
	printf("\tEnter Purchase Amount: ");

           { validate =scanf("%f", &purchaseAmount);
		if (validate!=0);			
		else goto skip_point;}
// Display tax and total sale amount
	
	if(iResponse==1)
	{	printf("\n\tThe tax amount for Del Mar is $%.2f\t", 
            		tax = (purchaseAmount*delMarTaxRate));
        	printf("\n\tThe total sale amount for Del Mar is $%.2f\t\n", 
            		purchaseAmount + (tax + .005));
       	}
         if(iResponse==2)
        {	printf("\n\tThe tax amount for Encinitas is $%.2f\t", 
            		tax =(purchaseAmount*encinitasTaxRate));
        	printf("\n\tThe total sale amount for Encinitas is $%.2f\t\n", 
            		purchaseAmount + tax );
       	}
        if(iResponse==3)
        {	printf("\n\tThe tax amount for La Jolla is $%.2f\t", 
            		tax = (purchaseAmount*laJollaTaxRate));                 
        	printf("\n\tThe total sale amount for La Jolla is $%.2f\t\n", 
            		purchaseAmount + (tax + .005));
        }
        		
		
		skip_point:
			if (validate==0)
				printf("\nInvalid purchase amount\n\n");
				printf("\nTry again? Y/N\t");
				scanf("%c",&option);
								
			while (option == 'y' || option == 'Y')
				goto start;
			if  (option =='n' || option == 'N')
			 	goto end;
			 	
			 
		
		

        end:            
        printf("\nPress any key to terminate program");
        
getch();   
  
}