LiquidCrystal::clear
void LiquidCrystal::clear();
This function clears the display, and sets the display’s cursor to (0,0) (the top-left corner of the display)
Usage:
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
lcd.begin(16, 2);
lcd.print("lkjahdfs"); //junk we want off the screen
lcd.clear();