save and load issue

/////////////////////////////////SAVE
/////////////////////////////////SAVE
/////////////////////////////////SAVE
file = get_save_filename(".lvl","")
if file_exists(file)
{
    i=show_message_ext("overwrite?","Yes","","No")
    if i = 0 || i = 3 exit;
}


f =file_bin_open(file,1)
writeint(other.f,instance_number(oWall))
with(oWallEditor)
{
    writeint(other.f,pointx_1)
    writeint(other.f,pointy_1)
    writeint(other.f,pointx_2)
    writeint(other.f,pointy_2)
}
writeint(f,instance_number(oLight))
with(oLight)
{
    writeint(other.f,x)
    writeint(other.f,y)
    writeint(other.f,color_get_red(lightColor))
    writeint(other.f,color_get_green(lightColor))
    writeint(other.f,color_get_blue(lightColor))
    writeint(other.f, image_xscale)
    writeint(other.f, image_yscale)
}

file_bin_close(f)

//////////////////////////////////LOAD
//////////////////////////////////LOAD
//////////////////////////////////LOAD
file = get_open_filename(".lvl","")
if !file_exists(file)
{
    show_message("file not found!")
    exit;
}


f =file_bin_open(file,0)
n = readint(f)
repeat(n)
{
    nx = readint(f)
    ny = readint(f)
    nx2 = readint(f)
    ny2 = readint(f)
    o=instance_create(nx,ny,oWallEditor)
    o.pointx_1 = nx
    o.pointy_1 = ny
    o.pointx_2 = nx2
    o.pointy_2 = ny2
    with(o){vector_wallset()}
}
show_message("made it to lights")
n = readint(f)
repeat(n)
{
    o = instance_create(readint(f),readint(f),oLight)
    o.lightColor = make_color_rgb(readint(f),readint(f),readint(f))
    o.image_xscale = readint(f)
    o.image_yscale = readint(f)
}
file_bin_close(f)