Code:
if (input[idx] < 48 || input[idx] > 57)
I find '0' clearer than 48.
Code:
{ // this whole code block is useless
char ch;
char input[10];
int idx, decimal_found ;
}
printf("\n\n Please enter a dollar amount you would like to convert. (US Dollars): ");
scanf("%f",&money);
// somewhere in here you should actually read something into input
decimal_found = 0 ;
/*Checks for validity of input entered by user for numerical value,retreived from Aruna Pandey*/
for (idx = 0 ; idx < strlen(input) ; idx++) // input is not initialized!
{
if (input[idx] == '.')
{
And, as someone mentioned, get rid of the fflush(stdin).