var images = new Array();
    images[0] = "home";
    images[1] = "tax";
    images[2] = "flood";
    images[3] = "service";
    images[4] = "about";
    images[5] = "contact";
    
    for(i=0;i < 6;i++){
      var myImage = new Image();
      myImage.src = "images/" + images[i] + "_on.gif";
      myImage.src = "images/" + images[i] + "_off.gif";
    }
    
    function navSwap(img){
      var theImage = document.getElementById(img);
      var offset = "http://dev.globi.ca/lereta/";
      if(theImage.src == offset + "images/"+img+"_off.gif"){
        theImage.src =  "images/"+img+"_on.gif";
      }
      else{
        if (theImage.src == offset + "images/" + img + "_on.gif") {
          theImage.src = "images/" + img + "_off.gif";
        }
      }
    }