/*ポップアップ.js*/
function showPopup(){
  if(document.getElementById){
    document.getElementById(myID).style.visibility = 'visible'
  } else {
    if(document.all){document.all(myID).style.visibility= 'visible'}
  }
}

function hidePopup()
{
  if(document.getElementById){
    document.getElementById(myID).style.visibility = 'hidden'
  } else {
    if(document.all){document.all(myID).style.visibility= 'hidden'}
  }
}
<!-- 呼び出し -->