login_on = new Image ( );
projectCycle_on = new Image ( );
login_off = new Image ( );
projectCycle_off = new Image ( );

login_on.src = "images/swap_login_18.jpg";
login_off.src = "images/login_18.jpg";

projectCycle_on.src = "images/swap_project_cycle.jpg";
projectCycle_off.src = "images/project_cycle.jpg";

function button_on ( imgId )
{
  if ( document.images )
  {
    butOn = eval ( imgId + "_on.src" );
    document.getElementById(imgId).src = butOn;
  }
}

function button_off ( imgId )
{
  if ( document.images )
  {
    butOff = eval ( imgId + "_off.src" );
    document.getElementById(imgId).src = butOff;
  }
}