function hide(num){
 if (num==1){
  //document.pic1.src='images/menu_block.gif';
  }
 if (num==2){
  //document.pic2.src='';
  }
 if (num==3){
  document.all.hidden3.style.display='none';
  //document.pic3.src='';
  }
 if (num==4){
  //document.pic4.src='';
  }
 if (num==5){
  document.all.hidden5.style.display='none';
  }
 }
function show(num){
 if (num==1){
  //document.pic1.src='images/menu_block2.gif';
  }
 if (num==2){
  //document.pic2.src='';
  }
 if (num==3){
  document.all.hidden3.style.display='block';
  //document.pic3.src='';
  }
 if (num==4){
  //document.pic4.src='';
  }
 if (num==5){
  document.all.hidden5.style.display='block';
  }
 }