I have a code for particle effect.
How to increase(decrease) alpha, for whole effect proportionally?

//*********ACTION made by Particle Project Smoke V 0.06*********//

BMAP* smoke_tga = "smoke.tga";

function initStartup_waterfallmy()

{

max_particles = 2000;

}




function alphaFade_waterfallmy(PARTICLE *p_waterfallmy)
{
p_waterfallmy.alpha -= 1 * time_step;
if (p_waterfallmy.alpha < 0) p_waterfallmy.lifespan = 0;
}

function partSet_waterfallmy(PARTICLE *p_waterfallmy)
{

var colourZ = 0;
set(p_waterfallmy,MOVE);
//set(p_waterfallmy,BRIGHT;
set(p_waterfallmy,TRANSLUCENT);
//set(p_waterfallmy,NOFOG);
//set(p_waterfallmy,BEAM);
vec_set(my.blue,vector(255 + random(0 ), 255 + random(0 ), 255 + colourZ + random(0 )));

vec_add (p_waterfallmy.vel_x, vector(4 + random(0 ), 25 + random(0 ), 0 + random(2 )));
vec_add (p_waterfallmy.vel_x, vector(0 + random(-1 ), 0 + random(-1 ), 0 + random(-1 )));
p_waterfallmy.alpha = 12.117 + random(40.313 );
p_waterfallmy.bmap = smoke_tga;
p_waterfallmy.size = 200 + random(900 );
p_waterfallmy.lifespan = 90 ;
p_waterfallmy.gravity = 1.010 ;
p_waterfallmy.event = alphaFade_waterfallmy;
}

action waterfallmy()
{

VECTOR partPos_waterfallmy;

while (1)

{
// var bkToOne = 1;

// while (bkToOne <= 100 )

// {

my.skill1 = 0;

while (my.skill1 < 171.660 )
{
my.skill1 += 1;
vec_for_vertex(partPos_waterfallmy, my, my.skill1);
effect(partSet_waterfallmy, 1, partPos_waterfallmy, nullvector);

set(my,VISIBLE);
reset(my,INVISIBLE);
set(my,TRANSLUCENT);
set(my,PASSABLE);


}

// bkToOne++;

// }

wait(1);

}

}