Really cheesy square root function

[Wynd]

int sqrt(int root)
{
	int i = 0;
	bool done = false;

	while(!done)
	{
		i++;
		if ((i*i) == root)
			done = true;
		else if (i == root)
		{
			cout<<"No whole root";
			done = true;
		}
	}

	return i;

}

This works is the square root is a whole number (25 for example), but how can I do a function that works with any number?