Using G4P GUI image buttons, how to use mouse pressed on the button, and make them go away after

I want my first page to have the image buttons i created with my gui, but then I want to create some sort of boolean/ mouse clicked when you click on them it'll change my programs page ( and the buttons will disapear). Is anyone familiar with this editor and can help me?

// Need G4P library
import g4p_controls.*;
int page=1;

int otisX, otisY= 200;
int maxX= 700;
int maxY= 200;

int W= 600, H= 600;

boolean OtisOver= false;
boolean MaxOver= false;

public void setup() {
  size(800, 600, JAVA2D);
  createGUI();
  customGUI();
}

public void draw() {
  page1();
  background(200);
  //pageSelector();
}


void pageSelector() {
  if (page==1) {
    page1();
  } else if (page==2) {
    page2();
  } else {
    page3();
  }
}
void page1() {
  background(#FF00FF);
  fill(250);
  rect(otisX, otisY, W, H);
  rect(maxX, maxY, W, H);
}
void page2() {
  background(#CE2121);
}
void page3() {
  background(#008000);
}
void mousePressed() {
  if (OtisOver (otisX, otisY, W, H)==true) {
    page2();
  }
  if (MaxOver (maxX, maxY, W, H)==true) {
    page3();
  }
}


boolean MaxOver(int x, int y, int w, int h) {
  if (mouseX >= x && mouseX <= x+w &&
    mouseY >= y && mouseY <= y+h) {
    return true;
  } else {
    return false;
  }
}

boolean OtisOver(int x, int y, int w, int h) {
  if (mouseX >= x && mouseX <= x+w &&
    mouseY >= y && mouseY <= y+h) {
    return true;
  } else {
    return false;
  }
}
public void customGUI() {
}