how do i add this code to my script?

//This is a product of Joey Bee Productions.  Please include in credits.


bmap loading_lv = <blank.bmp>;  //Loading screen
panel loadingscreen {
	bmap = loading_lv;   //loading screen name
	flags = refresh,d3d;
}

function load_level()
{
	loadingscreen.pos_x = (screen_size.x - bmap_width(loading_lv))/2;  //centers loading screen
	loadingscreen.pos_y = (screen_size.y - bmap_height(loading_lv))/2;

loadingscreen.visible = on;  //displays loading screen	
wait(3);
wait(-2);
loadingscreen.visible = off;  //clears screen
bmap_purge(loading_lv); 
LOAD_LEVEL <-->levelname<-->;  //level name 
  
}}


ACTION levelchange //*assign this to a map entity blocking the way out of the level*/!!!!
{

MY.INVISIBLE = ON;       //makes entitie invisible
MY.ENABLE_IMPACT = ON;   //enables player impact
MY.EVENT = load_level;  //function name

}