Dunno but why do you have braces (klammern) behind the panel name?

Try this code if it works at all:
Code:
BMAP Meinebmp = "Anzeige.tga"; //Bild_location

PANEL Anzeige1
{
  pos_x = 0; //Position X
  pos_y = 0; //Position Y
  layer = 3; //Ebene
  bmap = Meinebmp; //alternativ Name
}



///////////////////////////////////////////////////////////

action markierung
{
  while(my != NULL)
  {
    c_trace(my.x,vector(my.x,my.y,my.z+500),IGNORE_ME|IGNORE_PASSABLE);
    if(you != NULL)
    {
       if(you.flag5 == ON)
       {
         anzeige1.VISIBLE = ON;
       }
    }
    
    wait(1);
  }
}