php弹出错误警告函数
//********弹出alert框并跳转到指定页面******//
function alert($message,$url='',$isAlert=true,$title='提示'){
echo '<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8" /><title>',$title,'</title></head><body>';
echo '<script type="text/javascript">';
echo $isAlert'alert("'.$message.'");':'';
echo $url=='''history.back();':'location.href="'.$url.'";';
echo '</script>';
echo '</body></html>';
exit();
}