How to save and delete some word in the text file in C++ without resetting it?

[judo11]

Every time I open my program the text file becomes empty and how can I save all the inputs in the text file I mean how can I still edit and see my last inputs? And here's my another problem every time I delete a name or an id number this program deletes all my inputs including those are who are not included so how can I delete a word or a text in the text file without affecting the other records, in short how to delete a word specifically?

#include<iostream>
#include<fstream>
#include<cstring>
using namespace std;

int main()
{
	static int totrec=0;    //totrec variable keep track for total variable entered
	{						//Initially Record scanned are Zero void main()
		int choice;
		char name[100];
		while(true)
		{
		cout<<"\n\n\nChoose your choice\nNOTE : one choice for one record(except viewing data)\n";
		cout<<"1) Scanning intial records\n";
		cout<<"2) Add records\n";
		cout<<"3) Modifying or append records\n";
		cout<<"4) View records\n";
		cout<<"5) Search Record\n";
		cout<<"6) Delete Record\n";
		cout<<"0) Exit\n";
		cout<<"Enter your choice : ";
		cin>>choice;
		while(choice<0&&choice>5)
    	{
    		cout<<"\nInvalid Choice\nTRY AGAIN\n"<<endl;
    		cin>>choice;
    	}
    	
    	while(!cin&&cin.fail()) 
		{ 
    		cout<<"\nInvalid Choice\nTRY AGAIN\n"<<endl;
    		cin.clear(); // clear the error 
    		// clear the input stream 
    		cin.ignore(10000,'\n'); 
    		cin>>choice;
		} 
		switch(choice)
		{
			  case 1:  //Scanning intial records
			  {
						ofstream outfile;
						outfile.open("emp.txt",ios::out);
						cout<<"\n\nPlease enter the details as per demanded\n";
						cout<<"\nEnter the name : ";
						cin.ignore();
						cin.getline(name, 100);
						outfile<<name<<endl;
						cout<<"Enter Age : ";
						int age;
						cin>>age;
				        outfile<<age<<endl;
						int id;
						cout<<"ID Number : ";
						cin>>id;
						outfile<<id<<endl;
						cin.ignore();
						totrec= totrec + 1;
						outfile.close();
			  }
			  break;
			  case 2:   //Appending records;
			  {
						ofstream outfile;
						outfile.open("emp.txt",ios::app);
						cout<<"\n\nPlease enter the details as per demanded\n";
						cout<<"\nEnter the name : ";
						cin.ignore();
						cin.getline(name, 100);
						outfile<<name<<endl;
						cout<<"Enter Age : ";
						int age;
						cin>>age;
						outfile<<age<<endl;
						string id;
						cout<<"ID Number : ";
						cin>>id;
						outfile<<id<<endl;
			
						totrec = totrec + 1;
						outfile.close();
			  }
			  break;
			  case 3:   //Modifying or append records
			  {
						ofstream outfile;
						outfile.open("emp.txt",ios::ate);
						cout<<"Are you interested in adding record\nenter y or n\n";
						char ans;
						cin>>ans;
						if(ans=='y' || ans=='Y')
						{
							cout<<"\n\nPlease enter the details as per demanded\n";
							cout<<"\nEnter the name : ";
							char name[20];
							cin>>name;
							outfile<<name<<endl;
							cout<<"Enter Age : ";
							int age;
							cin>>age;
							outfile<<age<<endl;
							string id;
							cout<<"ID Number : ";
							cin>>id;
							outfile<<id<<endl;
							cin.ignore();
							totrec = totrec + 1;
						}
						outfile.close();
			  }
			  break;
			  case 4:  //Viewing records
			  {
						ifstream infile;
						infile.open("emp.txt",ios::in);
						const int size=80;
						char line[size];
						int counter=totrec;
						while(counter > 0)
						{
							infile.getline(line,size);
							cout<<"\n\nNAME     : "<<line<<endl;
							infile.getline(line,size);
							cout<<"AGE      : "<<line<<endl;
							infile.getline(line,size);
							cout<<"ID NUMBER: "<<line<<endl;
							counter--;
						}
						infile.close();
			  }
			  break;
			  case 5:  //search
			  {
						char search[100];
						int offset;
						string line;
						
						ifstream infile;
						infile.open("emp.txt");
						cout<<"Type the name you want to search"<<endl;
						cin.ignore();
						cin.getline(search, 100);
	
						if(infile.is_open())
						{
							if(!infile.eof())
							{
								getline(infile,line);
								if((offset=line.find(search, 0))!=string::npos)
								{
									cout<<search<<" has been found in the text file"<<endl;
								}
								else
								{
									cout<<"No results found!"<<endl;
								}
							}
							infile.close();
						}
						else
						cout<<"Could not open file"<<endl;
			  }
			  break;
			  case 6://delete
			  {
				string line; 
				char deleteline[100];
				ifstream stopword;
				stopword.open("emp.txt");
				if (stopword.is_open())
				{
					if ( getline (stopword,line) )
					{
						cout << line << endl;
					}
					stopword.close();
				}

				else cout << "Unable to open file";

				ofstream temp;
				temp.open("temp.txt");

				cout << "Please input the stop-word you want to delete..\n ";
				cin.ignore();
				cin.getline(deleteline,100);

				if (getline(stopword,line))
				{
					if (line != deleteline)
					{
						temp << line << endl;
					}
				} 
				temp.close();
				stopword.close();
				remove("emp.txt");
				rename("temp.txt","emp.txt");
				cout <<endl<<endl<<endl;
			  }
			  break;
			  case 0  :
			  {			  
					return 0;
			  }
			  default :  cout<<"\nInvalid Choice\nTRY AGAIN\n";
			  }
			}
			
		}
	}