function startSlides(num){nextSlide(0, num);}
function nextSlide(i,num){if(i>=num)i=0;showSlide('aircraft',i);setTimeout('showSlide(\'people\','+i+')',2500);setTimeout('nextSlide('+(i+1)+','+num+')',5000);}
function showSlide(type,idx){Element.removeClassName(type+idx,'hidden');setTimeout('hideSlide("'+type+'","'+idx+'")',5000);}
function hideSlide(type,idx){Element.addClassName(type+idx, 'hidden');}