this is my full script

// test9.wdl
var idle_percent = 0;
var walk_percent = 0;
var video_mode = 9;
var video_depth = 16;
var temptilt = 0;
var move_vec[3] = 0,0,0;




function main()
{

video_mode = 9;
video_depth = 16;
level_load("test9.wmb");

wait(2);
}


action player_move()
{
player = me;
camera.genius = player;

wait(1);

while (1)
{
move_vec[0] = (key_w - key_s)*3*time;
move_vec[1] = (key_q - key_e)*2*time;
player.pan += (key_a - key_d)*4*time;
ent_move(move_vec,NULLVECTOR);



if (move_vec[0]==0&& move_vec[1]==0)
{
idle_percent = (idle_percent +5*time)%100; ent_animate(me,"idle",idle_percent,ANM_CYCLE);
}
else
{
walk_percent = (walk_percent+sign(move_vec[0])*5*time)%100;
ent_animate(player,"walk",walk_percent,ANM_CYCLE);

}

// camera updates
vec_set (Camera.x,player.x);
camera.z += 27;
camera.pan = player.pan;
temptilt += (key_pgup - key_pgdn)*4*time;
if (key_home ==1) //reset camera tilt
{
temptilt =0;
}
if (temptilt > 75)
{
temptilt = 75;
}
else
{
if (temptilt <-75)
{
temptilt =-75;
}
}
camera.tilt =0+temptilt;

wait(1);
}
}

I created this script by following an tutorial of creating a fps.