//preload images for navigation
if (document.images)
{
  //Preload navigation mouse over images
  pic1= new Image();  pic1.src="/global/images/home_off.jpg"; 
  pic2= new Image();  pic2.src="/global/images/home_on.jpg"; 
  
  pic3= new Image();  pic3.src="/global/images/who_we_are_off.jpg"; 
  pic4= new Image();  pic4.src="/global/images/who_we_are_on.jpg"; 
  
  pic5= new Image();  pic5.src="/global/images/how_it_works_off.jpg"; 
  pic6= new Image();  pic6.src="/global/images/how_it_works_on.jpg"; 
  
  pic7= new Image();  pic7.src="/global/images/find_tutor_off.jpg"; 
  pic8= new Image();  pic8.src="/global/images/find_tutor_on.jpg"; 
  
  pic9= new Image();  pic9.src="/global/images/be_tutor_off.jpg"; 
  pic10= new Image();  pic10.src="/global/images/be_tutor_on.jpg"; 
  
  pic11= new Image();  pic11.src="/global/images/math_worksheets_off.jpg"; 
  pic12= new Image();  pic12.src="/global/images/math_worksheets_on.jpg"; 
  
  pic13= new Image();  pic13.src="/global/images/news_press_off.jpg"; 
  pic14= new Image();  pic14.src="/global/images/news_press_on.jpg"; 
  
  pic15= new Image();  pic15.src="/global/images/contact_us_off.jpg"; 
  pic16= new Image();  pic16.src="/global/images/contact_us_on.jpg"; 
}