string stops at first letter

Hey, can anyone help me figure out why the program keeps stopping with the first letter instead of following through the string??

Code:

#include <iostream>
#include <string>


using namespace std;


bool isVowel (char);
string noVowelString (string);


int main ()
{
	string str;


	cout<<"Enter a sentence: ";
	cin>>str;
	cout<<endl;


	cout<<"The sentence with the vowels removed is "<<noVowelString(str)<<endl;


	
    system("pause");
    return 0;
}


bool isVowel (char ch)
{
	switch (ch)
	{
	case 'A':
	case 'E':
	case 'I':
	case 'O':
	case 'U':
	case 'a':
	case 'e':
	case 'i':
	case 'o':
	case 'u':
		return true;
	default:
		return false;
	}
}


string noVowelString (string tStr)
{
	string :: size_type len=tStr.length();


	bool foundVowel = false;


	string :: size_type i;


	for (i = 0; i < tStr.length; i++)
	{
		if (isVowel (tStr[i]))
		{
			tStr.erase (i, 1);
			foundVowel = true;
		}


		else
			tStr = tStr.substr (i, 1);
	}
	return tStr;
}

You can't use the extraction operator>> to extract sentences. The extraction operator>> stops processing the string when it encounters a white space character. If you want your string to contain white space characters I recommend you try using the getline() function.

Jim

You're also modifying the string as you iterate over it, which spells disaster.