function changePic(img_name,img_src) {
  document[img_name].src=img_src;
}

function checkSize() {
    var myWidth = 0, myHeight = 0;
    if( typeof( window.innerWidth ) == 'number' ) {
      myWidth = window.innerWidth; myHeight = window.innerHeight;
    } else if( document.documentElement && ( document.documentElement.clientWidth ||document.documentElement.clientHeight ) ) {
      myWidth = document.documentElement.clientWidth; myHeight = document.documentElement.clientHeight;
    } else if( document.body && ( document.body.clientWidth || document.body.clientHeight ) ) {
      myWidth = document.body.clientWidth; myHeight = document.body.clientHeight;
    }
    browserWidth  = myWidth;
    browserHeight = myHeight;
    
    if (browserWidth<pageWidth) browserWidth=pageWidth;
  }


  function setLayer(name,action) {
    if (document.layers) {
      if (action) {
        checkSize();
        document.layers['layer'+name].visibility = visible;
        document.layers['layer'+name].left = ((browserWidth/2)-(pageWidth/2))+layerDist[name];
      } else {
        document.layers['layer'+name].visibility = hidden;
      }
    } else {
      if (action) {
        checkSize();
        document.all('layer'+name).style.visibility = visible;
        document.all('layer'+name).style.left = ((browserWidth/2)-(pageWidth/2))+layerDist[name];
      } else { 
        document.all('layer'+name).style.visibility = hidden; 
      }
    }
  }

  
  function changeLayer(name, action) {
    if (action) {
      if (dumpLayer!=null&&dumpLayer!=name) {
        setLayer(dumpLayer,false,0);
      } 
      dumpLayer = null;
      setLayer(name, action, layerDist[name]);      
    } else {
      dumpLayer = name;
      setTimeout("checkDump()",2500);
    }
  }
  
  function checkDump() {
    if (dumpLayer!=null) {
      setLayer(dumpLayer,false,0);  
      dumpLayer = null;
    }
  }
  
  
  function eachLayerhidden() {
    for (var i=0; i<layerDist.length; i++) {
      setLayer(i,false);
    }  
  }