41                 $all = array(
"ne", 
"nw", 
"se", 
"sw");
 
   42                 if(in_array((
string)$a_position, $all))
 
   44                         $this->position = (string)$a_position;
 
   65                 $this->columns = (int)$a_value;
 
   86                 $this->margin_x = (int)$a_x;
 
   87                 $this->margin_y = (int)$a_y;
 
   97                 return array(
"x"=>$this->margin_x, 
"y"=>$this->margin_y);
 
  109                         $this->background = $a_color;
 
  130                 $a_value = (float)$a_value;
 
  131                 if($a_value >= 0 && $a_value <= 1)
 
  133                         $this->opacity = $a_value;
 
  156                         $this->border = $a_color;