<?php
if($MySumit)
{
  echo "<script language=javacsript>\n";
  echo "window.open()\n"; //写上你的javascript
  echo "</script>\n";
}
?>...
<form action="<?php echo $PHP_SELF ?>" method=post>
...
<input type=submit name=MySubmit value="现实对话框">
</form>
...