class bank
{


    public:

    char username[100], password[16];

            void prompt()
           {
		system("cls");
		cout<<"\n ENTER YOUR USERNAME :";
	        cin>>username;

		cout<<"\n ENTER YOUR PASSWORD: ";
		cin>>password;
           }

	    void check_pass(char[],char[]);

};


void bank::check_pass(char a[100],char b[16])
{

    char str[100] , str1[16], str3[100]= "51097" ;
    float i;
     long pos; /* stores current file position */

          /* open text file in both read/write mode */     

         fstream b_file("new.txt",ios_base::in|ios_base::out);

          /*checks for username till end of file */
	     while( (strcmp(a,str) != 0)&&(! b_file.eof() ) )
	    {
		b_file>>str;
	       b_file>>str1;
            }

              /* checks username and password */
              if( (strcmp(a,str) == 0) && (strcmp(b,str1) == 0) )

             {
                b_file>>str1;
                cout<<"\n USER :  " <<a;
                cout<<"\n ACCOUNT NO: "<<str1;
                b_file>>str1;

               cout<<"\n BALANCE : "<<str1<<" Rs";


                 pos = b_file.tellg();  /* gets position */
                
                 /* made to point to exact location */

                b_file.seekg( pos- strlen(str1) ); 


                    for(int i = 0; i <= strlen(str1) ; i++)

                   {
                      b_file<<"  "; /* clears the present balance (in file) */
	            }

                    b_file.seekg( pos - strlen(str1) );

                    b_file<<str3; /*writes the string to exact location */
              }

             else
             {

              system("cls");
              cout<<"\n\n CHECK YOUR USER/PASSWORD IS CORRECT \n\n";
             }

             b_file.close();

}




int main()
{

	 bank b1, b2;

	  char  ex;

           for(;;)

          {

	    b1.prompt();

            b2.check_pass( b1.username, b1.password );

            cout<<"\n\n\n Enter 'e' for exit :";

            cin>>ex;

            if(ex=='e') exit(1);

         }

}