///button_align_y(region, _unit%)
function align_y() {

	var zone = argument[0];

	if (argument_count > 1)
	{
	    var percent = argument[1];
	    var deplacement = global.unit * percent;
	}
	else
	    var deplacement = 0;

	switch(zone)
	{
	    case region.mid_left:
	    case region.mid_right:
	        var y_start = global.window_height * 0.7;
	    break;
    
	    case region.bot_left:
	    case region.bot_right:
	        var y_start = global.window_height * 0.9;
	    break;
    
	    case region._100:
	        var y_start = global.window_height;
	    break;
	}

	return y_start + deplacement + __view_get(e__VW.YView, 0);


}