function roll_on ( imgId,imgName )
{imgId.firstChild.src = '/img/menu_hover_'+imgName+'.gif';}

function roll_off ( imgId,imgName )
{imgId.firstChild.src = '/img/menubg_'+imgName+'.gif';}
preload_image = new Image(25,25); 
preload_image.src="/img/menu_hover_02.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menu_hover_03.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menu_hover_04.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menu_hover_05.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menu_hover_06.gif"; 
preload_image = new Image(25,25); 
preload_image.src="/img/menubg_02.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menubg_03.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menubg_04.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menubg_05.gif";
preload_image = new Image(25,25);  
preload_image.src="/img/menubg_06.gif";