//tooltip.js
var tool_layer = document.createElement("div");
tool_layer.style.position = "absolute";
tool_layer.style.visibility = "hidden";
document.body.appendChild(tool_layer);

//Define style for message box here:
tool_layer.style.border = "1px solid black";
tool_layer.style.padding = "2 2 2 2";
tool_layer.style.backgroundColor = "white";

var tooltip={
  displayed:false,
  on:function(message){
    tool_layer.innerHTML = message;
    this.displayed = true;
    tool_layer.style.visibility = "visible";
  },
  off:function(){
    this.displayed = false;
    tool_layer.style.visibility = "hidden";
  },
  move:function(evt){
    var dist = 15;
    if(this.displayed){
      if (document.addEventListener) {
        tool_layer.style.left = ((evt.clientX + window.pageXOffset)+dist) + 'px';
        tool_layer.style.top = ((evt.clientY + window.pageYOffset)+dist) + 'px';
      }
      else if (window.opera) {
        tool_layer.style.left = ((evt.clientX + window.pageXOffset)+dist) + 'px';
        tool_layer.style.top = ((evt.clientY + window.pageYOffset)+dist) + 'px';
      }
      else if (window.event) {
        if (document.compatMode && document.compatMode!= 'BackCompat') {
          tool_layer.style.left = ((event.clientX + document.documentElement.scrollLeft)+dist) + 'px';
          tool_layer.style.top = ((event.clientY + document.documentElement.scrollTop)+dist) + 'px';
        }
        else {
          tool_layer.style.left = ((event.clientX + document.body.scrollLeft)+dist) + 'px';
          tool_layer.style.top = ((event.clientY + document.body.scrollTop)+dist) + 'px';
        }
      }
      else if (document.layers) {
        tool_layer.left = evt.pageX+15;
        tool_layer.top = evt.pageY+15;
      }
    }
  }
}