txt_hide('div01');
txt_hide('div02');

function txt_hide(tagnam1){
  document.getElementById(tagnam1).style.display='none';
}
function txt_flip(tagnam1){
  if (document.getElementById(tagnam1).style.display == '') {
    document.getElementById(tagnam1).style.display='none';
  } else {
	txt_hide('div01');
    txt_hide('div02');
    document.getElementById(tagnam1).style.display='';
  }
}