how to add new records to a data base by code

[twilight lover]

i write a small prog with builder c++ 5 that extract lines from text
file then add them into Paradoxe7 table these lines will appear in
a DBGrid on the Form by a click on Button1
the file contains many paragraphs each paragraph has the same end line
"end" , like this ;
line1
line2
line3
...
end
line1
line2
line3
...
end
...
feof
------------------this is my sample code-----------------------
---------------------------------------voici l'exemple de code-----------------------------------------------------
void __fastcall TForm1::FormCreate(TObject *Sender)
{
Table1->Open();
}

FILE*readflot;
char line[80]; /* var used to save each read line */

const char Read_FILE[10]="M.txt"; /* nom du fichier */


void Analyze() /* test if end of paragraph and insert read line into Table1 */
{
if(AnsiStrPos(line,"end")!=NULL)
{
Form1->Table1->Insert();
Form1->Table1->FieldByName("lines")->Value=line;
}

}
void __fastcall TForm1::Button1Click(TObject *Sender)
{
readflot=fopen(Read_FILE,"r"); /*read*/
if (!readflot)
{
Form1->Edit1->Text= "file opening operation's Impossible" ;
}
else /* fichier en lecture accessible */
{

while(!feof(readflot))
{
fgets(line,80,readflot) ;
Analyze();
} /* (feof(readflot)) */
fclose(readflot);
}
}

----------------------end of program------------------------------------------------
anyone can give me the reasen why the debugger send me when i execute then i click on
Button1 "DBEngine ERROR 'key violation' " after it fills one record in DBGrid ?
so my problem is " how to add new records to a data base by code automatiquely "

i tried to make google search but without a result

sorry for my bad english and thanks in advance