error trapping with char's

[craig_phillips2]

i am reading in values from a menu. however, if the user enters a char instead of an int, which is the type of the variable for reading values; the program goes into a never ending loop. How do i scanf the value into a char, check it is numerical, ie a number. and then convert it into an int. Some of this i know, like the conversion. I use atoi to convert the char to an int.

Here is my example code:

do{
  bInValid = true;
  printf("\n\nPlease enter an option: ");
  scanf("%d",&iChoice);

  if(iChoice < 1 || iChoice > iNumOpts)
  {
    bInValid = false;
    printf("\n\n*** Input error, try again! ***");
  }
}while(!bInValid);
if(iChoice == 1)
{
  if(iVal == 1)
    iChoice = 0;
  else
    iChoice = iVal / 10;
}
else
  iChoice = iVal * 10 + iChoice;
		
  clrscr();

  return iChoice;