Custom input stream function

[ShiHao]

Hello there, i am currently working on a custom istream function for a school assignment but i am not quite sure if i am heading towards the right direction or if it can be improved in any other way. If you have any comments or i made some mistakes, feel free to point them out. Thanks!

- User is able to key in 3 lines of text and it would be concatenated into a single string. Enter keypress are replaced by empty space.

istream & operator>> (istream & is, MyString & aMyString)
{	
        int tries = 3; 
	char buffer[200] = {'\0'};
	aMyString.Clear();

	do
	{
	        do
		{	
			is.get(buffer, 200);
			if(is.peek() != '\n')
                        {
			    aMyString.Append(buffer);			
                        }
                        else
                        {
                            tries -= 1;
                            if(tries > 0)
                            {
                                 aMyString.Append(" ");
                            }
                        }
		}while ((int)strlen(buffer) == 199);
	}while (tries > 0)
		
	is.sync();
	return is;
}
ShiHao
UAT Student