Files Delphi

Title: Add Line into the end of a file
Question: You want to write a line in a large file, use this procedure to do this.
Answer:
procedure AddLine_InFile(sLine: String; const FilePath: string);
{
sLine = String that go to the end of file.
FilePath = FullPath of the file.
}
var
pLog: Textfile;
begin
try
AssignFile(pLog, FilePath); // Assing a Path to TextFile.
if not FileExists(FilePath) then // Check Existence.
Rewrite(pLog, FilePath); // If not Make a new file.
Append(pLog); // Set Current line as the end.
WriteLn(pLog, sLine); // Write sLine if file.
finally
CloseFile(pLog); // Close the file.
end;
end;