ok then add this global var:

var transparency_var = 50;//this is the alpha variable.
var transparent_bool = 1;//this is the on/off switch, i you set it to 0,no transparency, anything else = transparent

and in the while loop of action ad these:
if(transparent_bool==0) reset(my,TRANSLUCENT);
else{
set(my,TRANSLUCENT);
my.alpha = transparency_var;
}