trouble w/assignment

[dP munky]

ok, basically i want to be able to input a string and find out if its a valid c identifier.......well, i got that part to work, the part that just wont come together is when i input ctrl+Z to end the program, it doesnt work???....can canybody help?? THANKS

//using msvs6.0

#include <stdio.h>



int StrSpn(char *str, char *cset)
{

	char *strPTR;
	char *csetPTR;

	strPTR = str;
	csetPTR = cset;

	while((*strPTR) != '\0') /* while strPTR != null and != to a space*/
	{	
				
		while((*csetPTR) != '\0' && (*strPTR) != (*csetPTR)) /*whle csetPTR != to null & strPTR != csetPTR*/
			{
				csetPTR++; /*increment csetPTR*/
			}		
			
			if ((*strPTR)==(*csetPTR))	/*if strPTR = csetPTR*/
			{
				strPTR++;				/*increment strPTR*/
				csetPTR = cset;			/*reset the value of csetPTR to the value of cset*/
			}
			
			else						/*else, the end of the string is not NULL*/
			{							/*break the loop*/
				if((*strPTR) != '\0');
				{
					return 3;
				}
				break;				
			}

	}
	
	return 0;	
}


int IsDigit(int ch)
{
		/*if the value at the first address of the string inputed is a number
		** the program will print that it is not a valid c identifier and return 0 */
		if( (ch >='0') && (ch <= '9') )
			return 0;
		
		if (ch == ' ')
			return 0;
	
	return 1;
}



int IsIdentifier(char *str)
{
	
	if(str != '\0')
	{
		if(StrSpn(str, "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ_0123456789") == '\0') 
		{						
			return 1;			/*when strspn gets to the end of the enterd string*/
								/*and all characters are valid, 1 is returned*/
		}						
								
		else
		{
			return 0;			/* if a digit which is not valid is found 0 is returned*/
			
		}
	
	}
	return 0;	
}






int main()
{
	char identifier[255];
	
	printf("The purpose of this program is to determine \n");
	printf("if the string entered is a valid c identifier\n");
	printf("Press Ctrl Z to exit the program\n");
	printf("Please Press Enter to Continue.\n");

	while (gets(identifier) != NULL)
	{
		printf("Enter an identifier: ");
		scanf("%[^\n]", identifier);
		/*Runs the IsDigit function, if the value of*/
		/*IsDigit returns a zero, end the program*/
				
		if(IsDigit(identifier[0]) == 0)
		{
			printf("\nThe string is NOT a valid c identifier\n\n");
		}
		
		else if(IsIdentifier(identifier) == 1)
		{
			printf("The string is a VALID C IDENTIFIER\n\n");
		}

		else if(IsIdentifier(identifier) == 0)
		{
			printf("The string is NOT a valid c identifier\n\n");
		
		
	}
	return 0;
}

[MrWizard]

Do your own homework digipen boy! Prosona Ghalli isn't going to like this...

[dP munky]

hey there man, i did do my own homework, im not cheating, i just want some direction.....besides, persanna said we could get help!