problem solved by windows.h
Code:
void clrscrn()
{
COORD coordScreen={ 0, 0};
DWORD cCharsWritten;
CONSOLE_SCREEN_BUFFER_INFO csbi;
DWORD dwConSize;
HANDLE hConsole = GetStdHandle(STD_OUTPUT_HANDLE);
GetConsoleScreenBufferInfo(hConsole, &csbi);
dwConSize = csbi.dwSize.X * csbi.dwSize.Y;
FillConsoleOutputCharacter(hConsole,TEXT(' '), dwConSize, coordScreen, &cCharsWritten);
GetConsoleScreenBufferInfo(hConsole, &csbi);
FillConsoleOutputAttribute(hConsole,csbi.wAttributes, dwConSize, coordScreen, &cCharsWritten);
SetConsoleCursorPosition(hConsole, coordScreen);
}