var system_over = new Image();
var system_out = new Image();

var service_over = new Image();
var service_out = new Image();

var help_over = new Image();
var help_out = new Image();

var company_over = new Image();
var company_out = new Image();

function loadImages() {	
   if (document.images) {
      system_over.src = "images/index_04_over.png"
      system_out.src = "images/index_04.png"

      service_over.src = "images/index_05_over.png"
      service_out.src = "images/index_05.png"

      help_over.src = "images/index_06_over.png"
      help_out.src = "images/index_06.png"

      company_over.src = "images/index_07_over.png"
      company_out.src = "images/index_07.png"
   }
}

function overImage( name) {
     document[name].src = eval(name+'_over.src');
}

function outImage( name) {
     document[name].src = eval(name+'_out.src');
}