parsing name problem

I was reviewing my parse author function for my book inventory problem and discovered it did not work if only one name ie first name was entered. I revised the code but it doesn't seem to work correctly please have a look.

Code:

void Author::parse_name(string tauthor){
    const string delims(" \t");
    int begIdx,endIdx,tIdx=0;
    //search for beginning of first word
    
    begIdx=tauthor.find_first_not_of(delims,0);
    
    //while beginning of word found 
    if (begIdx!=string::npos){
        // end or word
        endIdx=tauthor.find_first_of(delims,begIdx);
        first_name=tauthor.substr(begIdx,(endIdx-begIdx));
        begIdx=tauthor.find_first_not_of(delims,endIdx);
        
        if (begIdx!=string::npos){
                endIdx=tauthor.find_first_of(delims,begIdx);
                tIdx=tauthor.find_first_not_of(delims,endIdx);
                // if tIdx is at end of tauthor string only first,last are given
                if (tIdx!=string::npos)
                {
                   middle_name=tauthor.substr(begIdx,endIdx-begIdx);
                   //extract lastname
                   begIdx=tauthor.find_first_not_of(delims,endIdx);
                   endIdx=tauthor.length();
                               
                   last_name=tauthor.substr(begIdx,endIdx-begIdx);
                }
                else
                {
                    last_name=tauthor.substr(begIdx,endIdx-begIdx);
                    middle_name="";
                }
        }
        else{
            last_name="";
            first_name=""; 
        }           
    }
    else{
         first_name="";
         middle_name="";
         last_name="";
    }
       
}

I spotted half the problem this morning:

Code:

void Author::parse_name(string tauthor){
    const string delims(" \t");
    int begIdx,endIdx,tIdx=0;
    //search for beginning of first word
    
    begIdx=tauthor.find_first_not_of(delims,0);
    
    //while beginning of word found 
    if (begIdx!=string::npos){
        // end or word
        endIdx=tauthor.find_first_of(delims,begIdx);
        first_name=tauthor.substr(begIdx,(endIdx-begIdx));
        begIdx=tauthor.find_first_not_of(delims,endIdx);
        
        if (begIdx!=string::npos){
                endIdx=tauthor.find_first_of(delims,begIdx);
                tIdx=tauthor.find_first_not_of(delims,endIdx);
                // if tIdx is at end of tauthor string only first,last are given
                if (tIdx!=string::npos)
                {
                   middle_name=tauthor.substr(begIdx,endIdx-begIdx);
                   //extract lastname
                   begIdx=tauthor.find_first_not_of(delims,endIdx);
                   endIdx=tauthor.length();
                               
                   last_name=tauthor.substr(begIdx,endIdx-begIdx);
                }
                else
                {
                    last_name=tauthor.substr(begIdx,endIdx-begIdx);
                    middle_name="";
                }
        }
        else{
            last_name="";
            first_name="";//***** here should be middle_name doh 
        }           
    }
    else{
         first_name="";
         middle_name="";
         last_name="";
    }
       
}

Anyhow now it is accepting single names as input but when it displays the name it shows for instance:Johnathan 2569
I can't figure out where the 2569 is coming from.