try:
echo "
<a href='#' onclick=window.open(`payment.php?Id='{$myrow[name]}'`,``,`width=300,height=320`)'>变更</a>";
echo "
<a href='#' onclick=window.open(`payment.php?Id='{$myrow[name]}'`,``,`width=300,height=320`)'>变更</a>";
<a href='#' onclick=window.open('payment.php?Id=<?echo $myrow[name];?>','','width=300,height=320')>变更</a>