C++ Pogram help!!!

[mrzods13]

I am having trouble with a program I have written, it allows the user to enter starting number, end number and number per line, the problem is I want to add in a check to see if the user enters a character instead of an integer. The proram works and is executable but when you enter a letter for example it goes into an infinite loop. Here is the code:

#include <iostream>
#include <string>
using namespace std;

int main()
{
	bool NoEnter = true;
	bool CarryOn = true;
	int StartNo = 0;
	int EndNo = 0;
	int NoPerLine = 5;
	int TestStuff = 0;
	string CO;

	while(CarryOn)
	{
		NoEnter = true;
		while(NoEnter)
		{
			StartNo = 0;
			EndNo = 0;
			NoPerLine = 5;
			TestStuff = 0;
			
			cout << "Starting number: ";
			cin >> StartNo;
			cout << "End number: ";
			cin >> EndNo;
			cout << "Number per line: ";
			cin >> NoPerLine;
			if(StartNo <=EndNo){}
			else
			{
				cout << "Enter an end number greater than or equal to start number\n";
				TestStuff = TestStuff + 1;
			}
			if(NoPerLine >= 1){}
			else
			{
				cout << "Numbers per line must be greater than 1\n";
				TestStuff = TestStuff + 1;
			}
			if(TestStuff == 0)
			{
				NoEnter = false;
			}
		}
		cout << "\n";
		for(int i = StartNo; i<=EndNo;i++)
		{
			cout << i << " ";
			if(StartNo == NoPerLine)
			{
				if(i % (NoPerLine) == 0 && i!=NoPerLine)
				{
					cout << "\n";
				}
			}
			else
			{
				if(i % (NoPerLine) == 0)
				{
					cout << "\n";
				}	
			}
	
		}
		cout << "\n";
		cout << "\nWould you like to go again? Y or N: ";
		cin >> CO;
		if(CO == "N" || CO == "n")
		{
			CarryOn = false;			
		}
		else
		{
			cout << "\n";
		}
	}
}

Any help would be greatly appreciated, this is an assignment for school but I just need help with that one thing, I have the thing up and running, hopefully I can get help on this one. Thanks in advance.

[Duthomhas]

Input validation: http://www.cplusplus.com/forum/beginner/18258/#msg92955
The part where my example complains is where you should recognize a non-numeric input. (That is, if cin is not good() after attempting to read a number.

Hope this helps.