var poc = 0;
var iwinTitle = window.document.title;
var lineCount = 0;
var lineHeight = 20;

function show_image(imgName, imWidth, imHeight) { 
  if (poc!==0) { iwin.close(); }; 
  
  url = imgName;
  resStr = "resizable=0,scrollbars=0";
                                                         
  // define window oversize
  winPlusWidth = 0;
  winPlusHeight = 0;
  // calculate window size
  winHeight = imHeight + winPlusHeight;
  winWidth = imWidth + winPlusWidth;
  // test if the window is not too large
  heightOK = true;
  if (winHeight>screen.availHeight)
    { winHeight = screen.availHeight-80;
  	  resStr=",resizable=1,scrollbars=1";
  	heightOK = false;
  	}
  if (heightOK==false)
    { winWidth = winWidth+22;
  	}								 
  if (winWidth>screen.width)
    { winWidth = screen.width-80;
  	  resStr=",resizable=1,scrollbars=1";
  	}								 
  
  // calculate centered window position
  winLeft = Math.round((screen.width-winWidth)/2);
  winTop  = Math.round((screen.availHeight-winHeight)/2);
  
  iwin = window.open("", "", "left="+winLeft+",top="+winTop+",height="+winHeight+",width="+winWidth+",directories=no,location=no,menubar=no,status=no,toolbar=no"+resStr);
  iwin.document.write("<html><head><title>", iwinTitle, "</title>");
  iwin.document.write("<link rel='stylesheet' type='text/css' href='showimage.css' title='formal'>");
  iwin.document.write("</head>");
  iwin.document.write("<body class=ImgShow>");
  iwin.document.write("<a href='' onClick=\"window.close(); return false;\"><img width=", imWidth," height=", imHeight," src=\"", url, "\" alt='' border=0></a>");
  iwin.document.write("</body></html>");
  poc++;
  return true;
    }


