//From one of the earlier AUMS...

bmap crosshair_map = <cross.tga>;//define the image file

panel crosshair_pan//create the window panel
{
bmap = crosshair_map;
layer = 20;
pos_x = 0;
pos_y = 0;
flags = transparent, overlay, refresh, d3d;
}


//then inside your player action
crosshair_pan.pos_x = screen_size.x / 2 - 32; // the crosshair has 16x16 pixels
crosshair_pan.pos_y = screen_size.y / 2 - 16;

//followed by the while loop
while (my.health > 0)
{
crosshair_pan.visible = on;

the rest of your code here...