function open_pic_window( pic_name, pic_width, pic_height, frame_name ) {
  mywin=window.open( "show_pic.php?image_name="+pic_name , frame_name, "toolbar=no,location=no,directories=no,scrollbars=no,status=no,menubar=no,resizable=no,width="+pic_width+",height="+pic_height );
  mywin.focus();
} 

function open_feat_window( ) {
  mywin=window.open( "show_feature.php", "feature", "toolbar=no,location=no,directories=no,scrollbars=yes,status=no,menubar=no,resizable=yes,width=500,height=600" );
  mywin.focus();
}