function SwapImgleft(ImgName,num){
 document.images[ImgName].src = BtnImgleft[num].src;
}
BtnImgleft = new Array();
for(i=0; i<=70; i++){
BtnImgleft[i] = new Image();
}

BtnImgleft[0].src = "images/nav_top.gif";
BtnImgleft[1].src = "images/nav_top_o.gif";
BtnImgleft[2].src = "images/nav_company.gif";
BtnImgleft[3].src = "images/nav_company_o.gif";
BtnImgleft[4].src = "images/nav_business.gif";
BtnImgleft[5].src = "images/nav_business_o.gif";
BtnImgleft[6].src = "images/nav_service.gif";
BtnImgleft[7].src = "images/nav_service_o.gif";
BtnImgleft[8].src = "images/nav_calendar.gif";
BtnImgleft[9].src = "images/nav_calendar_o.gif";
BtnImgleft[10].src = "images/nav_contact.gif";
BtnImgleft[11].src = "images/nav_contact_o.gif";